A manual for students preparing for examination at Apothecaries' Hall, or other medical examinations
Steggall, John, 1795?-1871
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BY JOHN STEGGALL, M.D. LICENTIATE OF THE ROYAL COLLEGE OF PHYSICIANS, LONDON, M.R.C.S. ETC. NINTH EDITION: LONDON: JOHN CHURCHILL, PRINCES STREET, SOHO. MACLACHLAN AND STEWART, AND CARFRAE AND SON, EDINBURGH 3 FANNIN AND CO., DUBLIN. MDCCCXKEXVITII. PRINTED BY C. ADLARD, BARTHOLOMEW CLOSE. TO JONATHAN PEREIRA, ESQ. F.R.S. LECTURER ON CHEMISTRY, MATERIA MEDICA, Sc. Se. THIS PUBLICATION IS DEDICATED, BY HIS VERY SINCERE AND ADMIRING FRIEND, JOHN STEGGALL. 29, Bloomsbury-square. CONTENTS. Regulations for Examination at Apothecaries’ Hall Chemical Decompositions Chemistry : : . . ° Organic Chemistry. ‘ Animal Chemistry . . : : Toxicology. ' Toxicological Chemistry, or Tests for the Principal Poisons Materia Medica : : : : Table of Preparations of Opium, Antimony, Mercury, and Arsenic Anatomy Physiology Practice of Medicine. Observations on Midwifery PREFACKH. ANOTHER edition of this work having been called for, in a shorter space of time than could have been contemplated, the author has endeavoured to render it still more acceptable to medical stu- dents, by extending almost every department. He wishes to direct the attention of the reader to the difference between the atomic numbers men- tioned under the Chemical Decompositions and those which are given in the Chemical Notes. In the first, they are arranged so as to conform with the numbers employed by Mr. Phillips; in the Chemical Notes, the atomic equivalents are in accordance with those adopted in Dr. Turner’s Chemistry, being the last agreed upon by che- mists, and presumed to be the most accurate. The difference, however, is not great; and, in- deed, in most instances, is merely fractional. The part on Materia Medica is diminished in quantity, and is intended to be simply a guide to the doses and classes and orders of the drugs, as eee Vi PREFACE. the subject has been more fully treated of in a separate work, in consequence of the importance attached to it at the various examinations in Great Britain. The anatomical part comprises an outline of the whole nervous system; and any deficiencies which may be discovered in the visceral anatomy will be found to be supplied in a work which the author has in the press, viz. “ A Manual for the College of Surgeons.” In conclusion, the author trusts that. the stu- dent will look upon this work in the light which is intended, and not flatter himself that the infor- mation contained in it will be a sufficient fund to conduct him through the difficulties of a medical examination. REGULATIONS, &c. FOR EXAMINATION AT APOTHECARIES’ HALL. Every Candidate fora certificate to practise as an Apothecary, will be required to produce testimonials : Of having served an apprenticeship of not less than five years to an Apothecary. No gentleman practising as an Apothecary in England or Wales can give his apprentice a legal title to examination, unless he is himself legally qualified to practise as an Apothecary, either by having been in practice prior to or on the Ist of August, 1815, or by having received a certificate of his qualification from the Court of Examiners. An apprenticeship for not less than five years to Surgeons practising as Apothecaries in ireland and Scotiand, gives the apprentice a title to be admitted to examination. Of having attained the full age of twenty-one years : As evidence of age, a copy of the baptismal register will be required in every case where it can possibly be procured. Of good moral conduct : A testimonial of moral character from the gentleman to whom the Can- didate has been an apprentice, will always be more satisfactory than from. any other person. And of having pursued the following course of Medical Study during not less than three winter and two summer ses- sions: the Winter session being understood to extend from the 1st of October to the middle of April, with a recess of fourteen days at Christmas, and the Summer session, from the 1st of May to the 31st of July. i Chemistry. First ; Winter ; Anatomy and Physiology. Session. Anatomical Demonstrations. Materia Medica and Therapeutics. First Botany; Summer S And such other branches of study as may improve the student’s Session. t general education. Anatomy and Physiology. Second : : Anatomical Demonstrations. Winter - : F : Dissections. Session. 3 tke i; eo Principles and Practice of Medicine. Second Botany, if not attended during the first Summer Session. Summer } ; re eatin. Forensic Medicine. Third Winter Session. Dissections. Principles and Practice of Medicine. viii REGULATIONS, &¢. MIDWIFERY. Midwifery, and the Diseases of Women and Children, two courses of Sixty Lectures each, in separate Sessions, and subsequent to the termination of the first Summer Session. Practical Midwifery, at any time after the conclusion of the first course of Midwifery Lectures. MEDICAL PRACTICE. The Student must attend Medical Practice during the full term of eighteen months; the first twelve months, i.e. from the commencement of the Second Winter Session, to the commencement of the third Winter Ses- sion, at a recognised hospital ; and the remaining six months either at a re- cognised Hospital, or a recognised Dispensary. The lectures on Botany may be attended during any Summer Session, either previous or subsequent to the first Winter Session. The sessional course of instruction in each subject of study, is to consist of not less than the following number of Lectures, ViZ. : One hundred on Chemistry. One hundred on Materia Medica and Therapeutics. One hundred on the Principles and Practice of Medicine. Sixty on Midwifery, and the Diseases of Women and Chil- dren. Fifty on Forensic Medicine. Fifty on Botany. The number of Lectures on Anatomy and Physiology, and of Anatomical Demonstrations, must be in conformity with the regulations of the Royal College of Surgeons of London, on these subjects. The Lectures required in each course, must be given on se- parate days. An Examination of an hour’s duration will be deemed equivalent to a Lecture. Students, when they present themselves for examination, must bring testimonials of having received instruction in Prac- tical Chemistry during their attendance upon the Lectures on Chemistry, Materia Medica, or Forensic Medicine ; and also of having attended a full Course of Clinical Lectures, and such instruction in Morbid Anatomy, as may be afforded them during their attendance at an Hospital. Every Student will be required to bring a testimonial of having dissected the whole of the human body once at least. The above course of study may be extended over a longer period than three Winter and two Summer sessions, provided the Lectures and Medical Practice are attended in the prescribed order, and in the required sessions. Students whose attendance on Lectures commenced prior to the ist of February, 1828, will be admitted to examination in REGULATIONS, &c. ix conformity with the Regulations published in September, 1826, _ viz. after an attendance on One Course of Lectures on Chemistry. One Course of Lectures on Materia Medica, Two Courses of Lectures on Anatomy and Physiology. Two Courses of Lectures on the Theory and Practice of Medicine. And six months’ Physician’s Practice at an Hospital, or nine months at a Dispensary. Those who began to attend Lectures subsequently to the Ist of February, 1828, and previously to the ist of October of the same year, in conformity with the Regulations of September, 1827, viz. after an attendance on One Course of Lectures on Chemistry. One Course of Lectures on Materia Medica and Botany. Two Courses of Lectures on Anatomy and Physiology. Two Courses of Lectures on the Theory and Practice of Medicine ; these last having been attended subsequently to the Lectures on Chemistry and Materia Medica, and to one course at least of Anatomy. And six months, at least, Physician’s Practice at an Hospital, or nine months at a Dispensary; such Attendance having commenced subsequently to the termination of the first Course of Lectures on the Principles and Practice of Medicine. Those whose attendance on Lectures commenced in October, 1828, must have complied with the Regulations of September, 1828, viz. by having attended Two Courses of Lectures on Chemistry. Two Courses of Lectures on Materia Medica and Botany. Two Courses of Lectures on Anatomy and Physiology. Two Courses of Anatomical Demonstrations. Two Courses of Lectures on the Theory and Practice of Medicine: these last having been attended subsequently to one Course of Lectures on Chemistry, Materia Medica, and Anatomy. And six months, at least, the Physician’s Practice at an hospital, (contain- ing not less than sixty beds,) or nine months at a Dispensary: such attend- ance to have commenced subsequentiy to the termination of the first course of I.ectures on the Principles and Practice of Medicine. All Students who began to attend Lectures in January, 1829, are required to have attended the Physician’s Practice at an Hospital for nine months, or at a Dispensary for twelve months, and also to have attended Two Courses of Lectures on Midwifery and the Diseases of Women and Children. Students whose attendance on Lectures commenced on or after January, 1831, must adduce proof of having devoted at least two years to attendance on Lectures and Hospital Prac- tice ; and of having attended the following Courses of Lectures : Gheuiistey eae Courses—Each Course consisting of ee not less than Forty-five Lectures. Materia Medica and Thera- De Courses—Each Course consisting of peutics : not less than Forty-five Lectures. x REGULATIONS, &C. Anatomy and } Two Courses : Of the same extent as required by Physiology : the Royal College of Surgeons of Apavomical ; } T wo Courses : London. Demonstrations : q Two Courses—-Each Course consisting of Principles not less than Forty-five Lectures, —To me be attended subsequently to the ter- Practice of Medicine mination of the first Course of Lectures ; on Chemistry, Materia Medica, and Anatomy and Physiology. One Course—Consisting of not less than Botany : Thirty Lectures,—To be attended be- ’ 2 tween the Ist of April and 3lst of October. Midwifery : and the Diseases of Women Two Courses. and Children; Barensic ‘Madicine: Pee Course—To be attended during second year. Students are likewise earnestly recommended to avail themselves of in- struction in Morbid Anatomy. The Candidate must also have attended, for Twelve Months, at least, the Physician’s Practice at an Hospital containing not less than sixty beds, and where a Course of Clinical Lectures is given; or for Fifteen Months at an Hospital where Clinical Lectures are not given; or for Fifteen Months at a Dispensary connected with some Medical School recognised by the Court. No part of this attendance can be entered upon until the termination of one entire year from the commencement of attendance on Lectures, nor until one course of Lectures, at least, on Chemistry, Materia Medica, Anatomy, and the Practice of Medicine, has been attended in the order prescribed by the Regulations. TESTIMONIALS. The Testimonials of attendance on Lectures, and Medical Practice must be given on a printed form, with which Students will be supplied, on application, at the under-mentioned places: In London, at the Beadle’s Office, at this Hall. an Edinburgh, at Messrs. Maclachlan and Stewart’s, book- sellers. In Dublin, at Messrs. Hodges and Smith’s, booksellers. In the provincial towns, where there are Medical Schools, from the gentlemen who keep the Registers of the Schools. No other form of Testimonial will be received: and no attendance on Lectures will qualify a Candidate for examination, unless the Lecturer is recognised by the Court. The names of the Lecturers recognised by the Court, may be seen on application to the several Gentlemen acting as Regis- REGULATIONS, &c, xi trars in the Provincial Schools, and at the Beadle’s Office at the Hall. The Teachers in London, Dublin, Edinburgh, Glasgow, and Aberdeen, recognised by the constituted Medical Authorities in those places respectively, are recognised by the Court; and Certificates given by the Medical Professors in Foreign Univer- sities are also recognised and received by the Court. i REGISTRATION. A book is kept at the Hall of the Society for the Registration, at stated times, of the names of Students, and of the Lectures, Hospitals, and Dispensaries they attend. All Students in London, are required to appear personally, and to register the several classes for which they have taken Tickets; and those only will be considered to have complied with the regulations of, the Court, whose names and classes in the register correspond with the testimonials of the Teachers. The book will be open for the registration of Tickets autho- rising the attendance ot Students on Lectures and Medical Prac- tice, in the months of October and May; and for the registra- tion of Certificates of having duly attended snch Lectures or Medical Practice in the months of April and August. Due notice of the days and hours of registration will be given from time to time. The Court also require Students at the Provincial Medical Schools to register their names in their own hand-writing, in the order above stated, with the Registrar of each respective school ; and the Registrars are requested to furnish the Court of Exami- ners with a copy of each registration immediately after its termination, as those Students only will be admitted to examina- Me whose registrations have been duly communicated to the ourt. PRELIMINARY EXAMINATION, Students may undergo their Latin Examination at any time after their first registration. A book is opened at the Beadle’s Office at the Hall, for the names of those gentlemen who are desirous of undergoing this Examination, to which twenty will be admitted on each successive Saturday, provided there are as many names on the list; when less than twenty names are on the list, no examination will take place. Candidates must attend at half-past three o’clock, and those who fail to pass this Examination satisfactorily, will not be readmitted until they appear for their general Examination. xii REGULATIONS, &c. EXAMINATION. Every person intending to offer himself for examination must give notice in writing to the Clerk of the Society, on or before the Monday previously to the day of Examination, and must also at the same time deposit all the required Testimonals at the office of the Beadle, where attendance is given every day, except Sunday, from Nine until Two o’clock. The examination of the Candidate for a certificate of qualifi- cation to practise as an Apothecary, will be as follows : In translating portions of the first four books of Celsus de Medicina, and of the first twenty-three chapters of Gregory’s Conspectus Medicine Theoretice : In Physicians’ Prescriptions, and the Pharmacopeia Lon- dinensis : In Chemistry : In Materia Medica and Therapeutics : In Botany: In Anatomy and Physiology : In the Principles and Practice of Medicine. This branch of the examination embraces an inquiry into the pregnant and puerperal states ; and also into the diseases of children. The examination of a Candidate for a certificate of qualifica- tion to act as an Assistant to an Apothecary, in compounding and dispensing medicines, will be as follows : In translating Physicians’ Prescriptions, and parts of the: Pharmacopeeia Londinensis: In Pharmacy and Materia Medica. By the 22d section of the Act of Parliament, no rejected Candidate for a certificate to practise as an Apothecary, can be re-examined until the expiration of six months from his former examination ; and no rejected Candidate as an Assistant until the expiration of three months. The Court meet in the Hall every Thursday, where Can- didates are required to attend ata Quarter before Four o’clock. For information relative to these Regulations, Students are referred to Mr. Sayer, Apothecaries’ Hall, every day (Sunday excepted), between the hours of Nine and Two o’Clock; and for information on all other subjects connected with the «* Act for better regulating the Practice of Apothecaries,”’ application is to be made to Mr. R. B. Upton, Clerk of the Society, at the Hall every day (Sunday excepted), between the hours of Nine and Ten. It is expressly ordered by the Court of Examiners, that no gratuity be received by any officer of the Court. Students will particularly oblige the Author by immediately making with a pen the following CORRIGENDA : Page 89 line 11 for oxygen read acid. 102 il iodine oxygen. 201 x hydro-sulphuret hydro-sulphurie acid. — 13 copper ; with copper and 242 11 after hydrochloric insert acid. 264 5 (from bottom) for gr.j. togr. iij. read gr. 4 to gr. j. 269 20 Cfrom top) Monand. Monad. 270 19 Creastoon Creasoton. 277 24 3): to Siij. gr. j. to gr. iij. 313 9 Cfrom bottom) for to the fourth from the lateral ventricle, ventricles. 470 4 above about. a) Cc on Soc Mater tate’ ated hs? Te bi et, CHEMICAL DECOMPOSITIONS, ies ACETUM DESTILLATUM. By distilling vinegar, acetic acid, with water and alittle alcohol, pass over in the first seven pints into the receiver, leaving the heavy impurities in the retort. Ifthe heat were continued, the acetic acid would be coloured, and obtain an empyreu- matic odour, resulting from decomposition of mucilaginous matter. Vinegar is made either from malt-liquors, or weak wines, or various fruits, such as gooseberries, &c. Hence it contains, amongst its impurities, mucilage, colouring matter, a little alcohol, some- times malic or tartaric acid; and in our own country we find sulphuric acid, on account of the law allowing one part of it to be added to 1000 parts of vinegar. We also find in vinegar, on some occasions, metallic impregnations, as of copper, lead, and tin, arising from the vessels which have been employed in preparing it. They may be discovered by their appropriate tests. The B i CHEMICAL DECOMPOSITIONS. strongest vinegar contains about 5 per cent. of real acetic acid, and a fluid ounce of it should be saturated by 58 grains of carbonate of soda. When a solution of chloride of barium is added to an ounce of vinegar, the precipitated sulphate of baryta should not exceed 1°14 grains. Should hydrosulphuric acid occasion no precipitate, it proves the absence of metallic salts. Déstelled vinegar should not be discoloured by hydrosul- phuric acid or ammonia; and no _ precipitate should be occasioned by acetate of lead, iodide of potassium, or nitrate of silver. Silver leaf, added to the solution, ought to afford no pre- cipitate on the addition of hydrochloric acid. These reagents refer to the possible presence of metallic salts generally, sulphuric acid, acetate of lead, hydrochloric acid, and nitric acids. Hydro- sulphuric acid would cause a dark precipitate, if tin, lead, or copper were present. Ammonia would turn the liquid blue if copper existed in it; acetate of lead would yield a white precipitate with sulphuric acid; iodide of potassium would throw down a yellow precipitate if lead were in the liquid; nitrate of silver, throwing down a white precipitate, would indicate the presence of hydro- chioric acid. If nitric acid existed in this acid, it would oxidize and dissolve silver, which would form a white chloride on the addition of hydro- chloric acid. I3 grains of crystallized carbonate of soda are saturated by 100 grains of this acid. Medical Uses. Vinegar is refrigerant, and considered to be antiseptic. It is seldom used much internally. Dr. Thomson recommends it CHEMICAL DECOMPOSITIONS. 5 during the administration of acetate of lead; with the idea of preventing that salt being converted into a carbonate. It is often used in the form of vapour in sore throats; externally, in lotions, for sponging the chest in some pulmonary diseases, or the body generally in fever. In the latter disease it is often sprinkled about rooms, with the impression that it has disinfecting qualities. Distilled vinegar is employed in pharmacy to form the acetates, all of which are very soluble in water. Dose. 3]. to 3ss. of vinegar. Prep. Acetum Colchici, Acetum Scillz, Liq. Ammonie Acetatis, Oxymel Scille. ACIDUM ACETICUM. Ingredients : | Acetate of soda, Sulphuric acid, Distilled water. Decomposition. 'The sulphuric acid, from its greater affinity, unites with the soda, forming sulphate of soda; the acetic acid is set free, and is separated by distillation. The heat should not be urged too long, for fear of decomposing even the sulphate of soda. Acetate of soda is obtained in the following manner: — By submitting wood to destructive distillation, anacid, named pyroligneous or acetic, is generated, contaminated with tarry eat To B 4 CHEMICAL DECOMPOSITIONS. this lime is first added, to form an acetate of lime; then sulphate of soda; when double de- composition ensues, affording acetate of soda and sulphate of lime. ‘The soluble acetate is removed, and heated so as to expel the tarry matter, and repeatedly dissolved and crystallized, until quite pure. This acetic acid has a specific gravity of 1.048. It is very volatile: when heated its vapour is com- bustible; 100 grains of it saturate 87 grains of crystals of carbonate of soda. It contains 30 per cent. of real acid. Anhydrous acetic acid is composed of: 3 oxygen. 3 X 8 == 24 3 hydrogen 3 < l= 3 4 carbon 4x 6= 24 — Atomic number 651 Medical Uses. This liquid, applied to the skin, acts as a rubefacient, and even raises a blister. It is also a mild escharotic. It is chiefly employed in pharmacy. Prep. Acetum Cantharidis, Acetas Morphie, Acetas Plumbi, Acetas Potassez, Oxymel. ACETUM CANTHARIDIS. This is a very useful preparation for producing speedy vesication: a piece of linen moistened with it is a convenient mode of applying it. It will often produce a blister in half an hour. It is not intended for internal administration. CHEMICAL DECOMPOSITIONS. 5 ACETUM COLCHICI. The proportion of the cormus to the liquid, is one ounce to seventeen ounces. According to some German chemists, the alkaline principle is not veratria, but a distinct substance, which they name Colchicia; therefore we have the acetate of colchicia in solution. ‘This vegetable alkali is best procured from the seeds of colchicum. Medical Properties. Diuretic, purgative, dia- phoretic, and sedative; most used in gout and theumatism. It does not agree with the stomach so well as the vinum colchici. Dose. 3}. to 5}j. ACIDUM BENZOICUM. By the application of heat to benzoin, benzoic acid rises, and condenses in the upper part of the apparatus. It is afterwards pressed between bibulous paper, to separate some oil which pro- ceeds from decomposition of a portion of the resin. The acid is a second time sublimed. Benzoin is not a gum-resin, but a compound of benzoic acid and resin, with a small quantity of a powerful aroma. We usually procure about 12 per cent. of acid from it. Benzoic acid may also be obtained by boiling benzoin in water, with car- 6 CHEMICAL DECOMPOSITIONS. bonate of lime. The benzoate thus formed is decomposed easily by hydrochloric or sulphuric acid; and the benzoic acid, from its sparing solu- bility, falls. It requires 200 times its weight of cold water for solution. When properly prepared, it should easily be volatilized by heat, readily dissolved by alcohol, sparingly by water; soluble in a solution of potash or lime, and be precipitated from such solutions by hydrochloric acid. Benzoic acid is a compound of a principle named benzule and oxygen, and cannot exist un- combined with water. ‘The composition of the anhydrous acid is: 14 carbon 14x6=> 8 5 hydrogen 5x 1= 5 3 oxygen 3.& & == 24 113 The crystals contain one water 9 eee Atomic number 122 Medical Properties. It is of no essential ser- vice as a medicine. Some imagine it to be a stimulating expectorant, and antispasmodic. It is most used on account of its odour. Prep. 'Tinct. Camphore Comp. ACIDUM CITRICUM. Ingredients: Lemon juice, Prepared chalk, Dilute sulphuric acid, Distilled water. CHEMICAL DECOMPOSITIONS. 7 Decomposition. In procuring this acid, the citric acid of the lemon-juice first combines with the lime, forming an insoluble citrate of lime, and carbonic acid is disengaged. ‘The citrate of lime is then decomposed by sulphuric acid, which unites with the lime, forming a comparatively in- soluble sulphate of lime, and soluble citric acid is set free, and obtained in crystals by evaporation. The object of this process is to separate the pure acid from the mucilage, which is washed away when the lime has united with the citric acid. The quantity of acid obtained from lemon- juice is about 113 <rs- froma pint. The satu- rating power of citric acid with the alkalies usually employed, may be seen by the following table: citric acid. lemon-juice. 3). of bicarbonate of potash requires ¢ gr. 14 Siijss. 9j. of carbonate of potash : for” er. 7 3s. Dj. sesquicarbonate of ammonia saturation¢ gr. 24 3Vj. Composition of anhydrous citric acid : 2 hydrogen 2 x 1 = 4 oxygen 4 8 == 32 4 carbon CSS (hc The crystals contain rather more than one equivalent of water, making its atomic number, according to Mr. Phillips, 70. Citric acid should be quite soluble in water. If the precipitate occasioned by adding acetate of lead to its solution is not soluble in dilute nitric acid, it would indicate the presence of sulphuric acid. The tartrate amongst the salts of potash, 8 CHEMICAL DECOMPOSITIONS. alone gives a precipitate with it, which is super- tartrate of potash, with a citrate of potash in solu- tion. If it be not entirely decomposed and dissi- pated by heat, some impurity is present. Medical Properties. Refrigerant and sedative, always given in combination with some alkali. It is preferable to tartaric acid, when we wish the neutral salt not to relax the bowels. Dose. 9Dj.; of lemon juice, 3ss. HYDROCHLORIC ACID. Ingredients: Chloride of sodium, Sulphuric acid, Distilled water. Decomposition. When the chloride of sodium, the acid, and half the water, are heated together, the water and the chloride are decomposed, the oxygen of the water combining with the sodium, forms soda; this, with the sulphuric acid, forms sulphate of soda; the hydrogen combining with the chlorine, forms hydrochloric acid gas, which passes over into the receiver, where it is absorbed by the water placed there for that purpose; sul- phate of soda remains in the retort. This liquid is a solution of hydrochloric acid gas In water; water can absorb 480 times its volume of this gas. -CHEMICAL DECOMPOSITIONS. 9 The tests of its purity are the following: it should be free from colour, and, by heat, entirely pass into vapour. It should yield no precipitate on the addition of chloride of barium, ammonia, or sesquicarbonate of ammonia. Gold is not affected by it. It does not remove the colour of sulphate of indigo. Its specific gravity is 1-160. 132 grains of crystals of carbonate of soda are saturated by 100 grains of it. When this acid is coloured, the impurities are either iron or free chlorine. ‘The chlorine is detected by the gold, which would be dissolved in it if present; also, by sulphate of indigo, which would lose its colour. If chloride of barium produces a precipitate, it shows the presence of sulphuric acid; ammonia and its sesquicarbonate are employed to precipitate any metals. ‘lhe presence of iron may be dis- covered by the ferro-cyanide of potassium, which throws down Prussian-blue. Composition of this acid: ] chlorine = 36 1 hydrogen = 1 Atomic number 37 Medical Properties. ‘onic and antiseptic. It is given with benefit in typhoid fevers, and scar- latina; in the treatment of worms, and in cases of abundance of the earthy phosphates in the urine. It has been erroneously supposed to be a solvent for all urinary calculi; although it may not be able to dissolve calculi in the bladder, through the medium of the circulation, still it has the power of arresting their rapid increase. It is also very BO 10 CHEMICAL DECOMPOSITIONS. useful as a gargle, when considerably diluted, in putrid sore throats. Dose. m.v. tom. xv. ACIDUM HYDROCYANICUM DILUTUM. Ingredients ; Ferrocyanide of potassium, Sulphuric acid, Distilled water. Decomposition. In this process water is decum- posed; its oxygen combining with potassium, forms potash, which the sulphuric acid immediately seizes upon, forming bisulphate of potash; the hydrogen, uniting with cyanogen, forms hydro- cyanic acid, which, by the heat, is driven into the receiver; and we have remaining in the retort a white salt, consisting of 1 equivalent of cyanide of potassium, and 2 of cyanide of iron. This acid is ordered to be kept from the light, in consequence of readily undergoing decomposition. From being colourless, it turns somewhat brown, and affords subsequently a blackish deposit, a compound of carbon, hydrogen, and nitrogen, named azulmic acid; and we find ammonia in the water. In the second formula, in which hydrochloric acid and cyanide of silver are employed, there is mutual decomposition; the chlorine goes over to CHEMICAL DECOMPOSITIONS. 11 the silver, and the hydrogen to the cyanogen, forming hydrocyanic acid, which is held in solu- tion, and subsequently poured off from the preci- pitated chloride of silver. The tests of its purity are these: It is colour- less, and entirely vaporizable by heat, with a peculiar odour. It slightly reddens litmus paper, and being volatile, the red colour so produced soon disappears. It is not coloured by hydro- sulphuric acid. In 100 grains of this acid, nitrate of silver, added, precipitates 10 grains of cyanide of silver, which are readily dissolved in hot nitric acid. Some other acid is present if a red preci- pitate falls, on the addition to it of the iodo-cyanide of potassium and mercury. Two grains of real hydrocyanic acid are contained in 100 grains of this dilute acid. By its volatility we ascertain the absence of solid matter. Hydrosulphuric acid not discolour- ing it, shows the absence of metallic salts. By the nitrate of silver its strength is ascertained; and the cyanide being dissolved by nitric acid, shows that itis not the chloride. Ifany other acid be present when the iodo-cyanide of potassium and mercury is added, there will be a red precipi- tate of biniodide of mercury. Composition of the anhydrous acid : 1 hydrogen = 1 ] cyanogen = 26 Atomic number 27 Medical Properties. Powerfully sedative. It diminishes the heart’s action, and also that of vessels in parts, which it can readily be applied 12 CHEMICAL DECOMPOSITIONS. to. Thus it checks vomiting in irritation or in subacute inflammation of the stomach; is useful in dyspepsia, depending on the preceding causes. It is given in asthma, hooping-cough, phthisis, and in coughs generally; it has been applied suc- cessfully to the surface of the body, in the treat- ment of some skin diseases. Dose. 5 minims, carefully increased. NITRIC ACID. Ingredients: | Nitrate of potash, Sulphuric acid. Decomposition. The sulphuric acid combines with the potash, forming bisulphate of potash, and the disengaged nitric acid is driven by the heat into the receiver. The acid is used in excess, in order to supply a sufficient quantity of water to form liquid nitric acid, and to prevent the disengagement of nitrous acid. Should any nitrous acid be present, it can readily be expelled by heat. Tests of its Purity. It entirely passes into vapour by heat. If nitrate of silver causes no precipitate, it shews the absence of hydro-chloric acid. ‘The chloride of barium causing no preci- pitate, shews that sulphuric acid is not present. Its specific gravity is 1.500; 217 grains of the crystals of carbonate of soda are saturated by 100 grains of this acid. CHEMICAL DECOMPOSITIONS. 13 Composition - 5 oxygen 5 xX 8 = 40 1 nitrogen 14 14 water 13.5 on 67.5 The liquid acid was formerly stated to contain 2 equivalents of water. Medical Properties. Tonic and antiseptic. It has been much used, largely diluted, as a drink in typhoid fevers; in which, like most other acids, it act by its sedative or anti-phlogistic properties; and, by restoring the circulation to its proper standard, becomes also tonic. It has been much and successfully employed in syphilis, when mer- cury was inadmissible. It is applied externally to fetid ulcers, in the quantity of 15 minims to a pint of water; and has been given internally in calculous affections, where the phosphates are predominant. Its vapour has been used to prevent or destroy contagion: hence it is often employed in purifying gaols, hospitals, ships, &c. ‘This is done by pouring sulphuric acid on nitrate of potash. Nitric acid is also used occasionally as an escha- rotic. Dropped into a hollow tooth, it is singu- larly efficacious in arresting that agonizing pain, toothach. DILUTE NITRIC ACID. This is made by mixing 1 ounce of nitric acid with 9 ounces of water. Dose. 20 to 60 minims. 14 CHEMICAL DECOMPOSITIONS. ACIDUM PHOSPHORICUM DILUTUM. Ingredients : Phosphorus, Nitric acid, Distilled water. Decomposition. Nitric acid is decomposed, giving oxygen to the phosphorus to form phos- phoric acid, binoxide of nitrogen being evolved: the acid is dissolved in the water. Composition of phosphoric acid: 5 oxygen 518i 2140 2 phosphorus 2 x 16 = 32 72 or according to some 36. Tests of its Purity. If chloride of barium and nitrate of silver produce precipitates insoluble in nitric acid, it is evident from the first that sulphu- ric acid is present; from the second, hydro-chloric; —the precipitates being sulphate of baryta or chloride of silver. Plates of copper or silver if acted on, would indicate the presence of nitric acid, and hydro-sulphuric would produce a precipi- tate if metallic salts were in the acid liquid. The sp. gr. of this liquid is 1.064, and 42 grains of the crytals of carbonate of soda saturate 100 grains of this acid, without any precipitation, which shews that no phosphate insoluble in water was held in solution by excess of acid. CHEMICAL DECOMPOSITIONS. 15 Medical Properties. Iti said to be tonic, and very serviceable in cases of exostosis, on which this acid is supposed to act chemically, that is, rendering the phosphate of lime soluble, and thereby diminishing it, if disposed to accumulate. Dose. m. Xx. to 31. ACIDUM SULPHURICUM DILUTUM. Composition. One ounce and a half of sulphu- ric acid, and fourteen ounces and a half of water. Sulphuric acid is obtained by burning a mixture of nitrate of potash and sulphur in large chambers lined with lead, with water at the bottom. One atom of the sulphur combines with two atoms of oxygen of the air, forming sulphurous acid, which is disengaged; another atom of the sulphur de- composes the nitric acid of the potash, and, uniting with three atoms of its oxygen, forms sulphuric acid; this combining with the potash of the nitrate, forms sulphate of potash, which is left in the earthen pot. ‘The nitrogen, and two atoms of the oxygen of the acid, form the binoxide of nitrogen, or nitrous gas, which, escaping into the air of the chamber, abstracts from it two atoms of oxygen, and then becomes nitrous acid. The sulphurous and nitrous acids, by meeting in the chamber, decompose each other, forming a crystalline solid, composed of sulphuric acid, hyponitrous acid, and watery vapour. When this solid is received 16 CHEMICAL DECOMPOSITIONS. by the water in the chamber, it is, in its turn, decomposed; the water retains the sulphuric acid, but the hyponitrous acid is resolved into nitrous acid and binoxide of nitrogen, which fly off with effervescence, and again attract fresh oxygen to combine with the sulphurous acid, which in the interim has been evolved. When the water is sufficiently acidulated, it is drawn off and heated until it becomes of a proper specific gravity. Sulphuric acid is seldom quite pure: it gene- rally contains a small quantity of sulphate of pot- ash and lead, the latter of which is often seen in the form of a white flocculent precipitate, when the acid is diluted with water. By mixing four parts of sulphuric acid with one of water, such condensation of volume takes place as to evolve heat of the temperature of 300 degrees. Composition of the anhydrous acid: 3 oxygen dX S24 1 sulphur =a 16 40 The liquid acid contains 1 water ee) 49 Medical Properties. Tonic, refrigerant, and antiseptic. ‘This acid is frequently given to check the night sweats in phthisis; with vegetable bitters after fevers, and especially with the sulphate of quinine and other preparations of cinchona. It is useful in most hemorrhages, acting as an astrin- gent and sedative; and has been added to oint- ments, to make a stimulating application. Dose. Of the diluted acid, from 10 to 20 mi- nims. CHEMICAL DECOMPOSITIONS. 17 ACIDUM TARTARICUM. Ingredients: Bitartrate of potash, Boiling water, Prepared chalk, Dilute sulphuric acid, Hydrochloric acid. Decomposition. When the bitartrate and half the chalk are boiled in water they are both de- composed, the bitartrate surrendering one equi- valent of its acid to the lime, forming a tartrate of lime, which falls to the bottom; carbonic acid escapes, and a tartrate of potash remains in solu- tion. The solution of tartrate of potash, instead of being rejected, is preserved to yield its tartaric acid also. ‘This is accomplished by adding the hydrochloric acid to the rest of the chalk ordered, when decomposition ensues; the chlorine with the calcium forms a chloride of calcium in solution, the hydrogen of the acid and oxygen of the lime form water, and carbonic acid is evolved; on the addition of this solution of chloride of cal- cium to the solution of tartrate of potash, fresh chemical changes occur; the chloride of calcium and tartrate of potash decompose each other; the chlorine with potassium forms a chloride of potas- sium, the oxygen of the potash passes to the lime, with which the tartaric acid combines, forming tartrate of lime. In this way the tartaric acid is all transferred from the potash to the lime; when 18 CHEMICAL DECOMPOSITIONS. sulphuric acid is added to the washed tartrate of lime, sulphate of lime is formed, and tartaric acid is set free, and, by evaporation, is procured in crystals. Tests of its Purity. It is totally soluble in water; this solution produces a precipitate of bi- tartrate, with any neutral salt of potash. If the precipitate produced in this solution by acetate of lead is insoluble in dilute nitric acid, it indicates that sulphuric acid in some form is present. Composition : 4 carbon 4x 6 = 24 5 oxygen 5x 8 = 40 2) hydrogen 2) x tle 2 Atomic number... 66 The crystallized acid contains one equivalent of water. Atomic number, 75. Medical Properties. Tefrigerant, and, with alkalies in the form of neutral salt, mildly purga- tive. Itis much employed as an ingredient in soda powders, to combine with the soda, and disengage carbonic acid; it is also a constituent of Seidlitz powders. Its saturating power is nearly the same as of citric acid. Dose. Dj. to 38s. CHEMICAL DECOMPOSITIONS. 19 AETHER SULPHURICUS. Ingredients : Rectified spirit, Sulphuric acid, Carbonate of potash, previously heated. Decomposition. When the acid and spirit are heated together, two equivalents of anhydrous sulphuric acid combine with two equivalents of alcohol to form sulphovinic acid. By the conti- nuance of the heat, this acid is resolved into two equivalents of anhydrous sulphuric acid, one of water, and one of zther; the latter of which, by heat, passes over into the receiver, and we have left in the retort the two equivalents of sulphuric acid with three of water. ‘The above is the expla- nation of Mr. Hennell. ‘This liquid is also named a dihydrate of olefiant gas, a hydrate of etherine, and by Dr. Kane, a protoxide of zethereum. Ano- ther mode of explaining the formation of ether, but admitted to be inaccurate, is that the sulphu- ric acid by its affinity for water, abstracts from two equivalents of alcohol, one equivalent of hydrogen and one of oxygen; that is, in the proportion for forming water; so that zther may be said to be a compound of two equivalents of olefiant gas, and one of water, whilst alcohol contains one of each. Qualities. Sp. gr..750, Exposed to the air, it entirely passes into vapour. Ather of the shops 20 CHEMICAL DECOMPOSITIONS. varies in specific gravity from .733 to .765. It slightly reddens litmus paper; it combines very sparingly with water, in the proportion of an ounce to a pint, and remains transparent. Composition : 4 carbon 4 2 5 hydrogen 65 1 oxygen x 6 al Hl at Ul 4 5 8 Atomic number... 37 Medical Properties. A. diffusible stimulant and antispasmodic. It is often prescribed in low states of the system with benefit; it is useful in hysteria, and asthma, and during the passage of biliary calculi, has been supposed not only to diminish pain, but likely to act as a solvent to the concretion. By its evaporation, considerable cold is produced; therefore, it is usefully introduced into cooling external applications. | Dose. 38s. to 3iss. OLEUM AXTHEREUM. Ingredients : Rectified spirit, Sulphuric acid, Solution of potash, Distilled water. CHEMICAL DECOMPOSITIONS. oy Decomposition. The excess of acid in this preparation prevents the formation of zther only, the products being some ether, an oily liquid, sulphurous acid and water; by exposing the su- pernatant liquid to the air for a day, the zther passes off in vapour, leaving the oily liquid be- hind; this is to be treated with solution of potash and water, to remove any sulphurous acid, and the residue is named ethereal oil, or oil of wine. Brande and Turner consider this liquid to be a compound of 1 sulphuric acid = 40 1 ether == 27 Atomic number rar The acid is intimately combined with the ether, as it affords no precipitate with chloride of barium, unless heat be applied to decompose the oil. Qualities. It has a peculiar odour; is ina very slight degree acrid; is quite soluble in sulphu- ric ether, and has no acid reaction. Sp. gr. 1.050. Medical Properties. The same as those of sulphuric ether: it is not given alone, but in the form of the spiritus etheris sulphurici compositus. SPIRITUS AUXTHERIS NITRICI. Ingredients : Nitric acid, Rectified spirit. 22 CHEMICAL DECOMPOSITIONS. Decomposition. ‘The nitric acid and alcohol are both decomposed. ‘The acid is resolved into hyponitrous acid and oxygen, and the alcohol is converted into ether; the oxygen of the acid combining with the disengaged elements of the alcohol, forming water, carbonic acid, malic, acetic, and tartaric acids. The nitric ether which is distilled over may be considered to be a hyponi- trite of ether, with uncombined alcohol. If the specific gravity exceeds .834, it is pro- bable that nitric acid or water in excess are pre- sent. ‘The litmus being strongly reddened, proves an abundance of acid, as also the effervescence occasioned by the carbonate of soda. Composition : 1 hyponitrous acid = 38 1 ether = Si Atomic number... 75 Medical Properties. Diffusible stimulant, and diuretic. Dose. 38. to 3ij. SPIRITUS AUTHERIS SULPHURICI COMPOSITUS. A mixture of sulphuric ether, rectified spirit, and ethereal oil. CHEMICAL DECOMPOSITIONS. a The advantage of this preparation is, that it is miscible with water, and therefore more conve- nient for internal administration. Dose. 388. to 5ij. ACONITINA. Ingredients: Aconite root, Rectified spirit, Dilute sulphuric acid, Solution of ammonia, Animal charcoal. Decomposition. By boiling the root with spi- rit, the aconitine with its acid is dissolved; and by distillation, this liquid is reduced to the thickness of an extract. When the sulphuric acid is added, it combines with the aconitine, and holds it i solution. To this ammonia is dropped, to abstract the acid, and precipitate the aconitine, which is collected and mixed with animal charcoal, to decolorize it. It is again combined with dilute sulphuric acid, and again precipitated by ammo- nia, and is ultimately procured in a pure form. Aconitina is a vegetable alkali; it is more solu- ble in sulphuric ether, less so in spirit, and very slightly in water. The vegetable alkalies or alkaloids are com- pounds of carbon, oxygen, hydrogen, and nitrogen. 24 CHEMICAL DECOMPOSITIONS. Medical Properties. A powerful anodyne, and narcotic remedy. It has been used successfully in some painful neuralgic affections, in very minute doses. It is chiefly used externally in the form of an ointment or alcoholic solution. Dose. Gr. z;, to be very carefully increased. AMMONIZ SESQUICARBONAS. Ingredients: Hydrochlorate of ammonia, Chalk. Decomposition. When heated together, the hydrochloric acid and lime of the chalk are de- composed; the chlorine of the acid combines with the calcium, forming chloride of calcium; the hydrogen of the acid, with the oxygen of the lime, forming water, which rises with the carbonic acid and ammonia, forming hydrated sesquicar- bonate of ammonia, chloride of calcium remaining in the retort. Composition : 13 carbonic acid, 1 ammonia, ] water. If this preparation could be made in vessels perfectly closed, the ammonia would be a carbo- nate, instead of a sesquicarbonate; during the sublimation, some water escapes, as also ammonia, which accounts for the preponderance of carbonic CHEMICAL DECOMPOSITIONS. 25 acid. Ammonia combines with carbonic acid in three proportions, viz., the monocarbonate, ses- quicarbonate, and bicarbonate. The first exists in spiritus ammoniz; the second in the prepara- tion under notice, and this sesquicarbonate be- comes bicarbonate by being kept, and somewhat exposed to the air, which occasions the escape of some more ammonia. Qualities. Tixposed to the air it passes into a powder, and loses some ammonia; it is entirely volatilizable. After being saturated with nitric acid, no precipitate is formed by adding chloride of barium, or nitrate of silver, shewing the absence of sulphuric and hydrochloric acids. Medical Properties. A diffusible stimulant, antispasmodic, antacid, and somewhat diaphore- tic; in large doses emetic. Asan emetic it may be of great benefit in narcotic poisoning. This sub- stance is often very serviceable in depressed states of the system, as in typhus, confluent small-pox, &c. &c. It is a stimulant and rubefacient, if applied externally. Dose. As a stimulant, gr. v. to gr. x. As an emetic, gr. Xx. to gr. Xxx. Prep. Lig. amm. sesquicarb.—Liq. amm. acet. —Cupri ammonio-sulphas. 26 CHEMICAL DECOMPOSITIONS. LIQUOR AMMONITZ. Ingredients: Hydrochlorate of Ammonia, Lime, Water. Decomposition. When the above ingredients are properly mixed and heated, the hydrochloric acid and lime are both decomposed; the chlorine combining with the calcium, forms chloride of cal- cium; the hydrogen and oxygen form water; by heat, the ammonia, which is set free, passes over with part of the water into the receiver. Liquor ammonie is a solution of ammoniacal gas In water. 