1864.] Dr. Wolf on the Magnetic Variations at Greenwich . 87 

Purpureine. 

When purpurine is dissolved in dilute ammonia, and exposed to the air 
for about a month in a warm place, ammonia and water being added from 
time to time as they evaporate, the purpurine disappears, whilst a new 
colouring matter is formed, which dyes unmordanted silk and wool of a 
fine rose-colour, but is incapable of dyeing vegetable fabrics mordanted with 
alumina. 

This new substance, which, from its mode of formation and physical pro¬ 
perties, is so analogous to orceine, I have called purpureine. When pure, 
it forms fine long needles of a deep crimson colour, insoluble in dilute acids, 
slightly soluble in pure water, and very soluble in alcohol and in water 
rendered slightly alkaline. Professor Stokes has examined purpureine 
optically, and finds the spectrum the same in character as that of purpurine, 
but different in position, the bands of absorption being severally nearer to 
the red end. 

From the analyses, purpureine seems to yield the formula C 66 H 24 N 2 O 20 . 

Nitropurpurine , 

When purpurine is dissolved in a small quantity of nitric acid, spec, 
grav. about *135, and heated to 100° C., it gives off red fumes, and on 
being allowed to cool, a substance separates in fine scarlet prisms, some- 
what like chromate of silver, only of a brighter colour. It is quite inso¬ 
luble in water, but slightly soluble in spirit; it is, however, soluble in strong 
nitric acid. When heated, it deflagrates. From this circumstance, and 
considering its mode of formation, it is evidently a nitre-substitution com¬ 
pound. I have therefore called it nitropurpurine. 

When alizarine and munjistine are subjected, in the manner above de¬ 
scribed for purpurine, to the joint action of ammonia and oxygen, substan¬ 
tive colours are produced, neither of which are crystalline. 

Action of Bromine on Alizarine. 

When alcoholic solutions of alizarine are mixed with water, and aqueous 
solution of bromine added, a yellow precipitate is produced; the solution 
filtered from this, after expelling the spirit by heat, deposits a deep orange- 
coloured crystalline compound, which, from the analyses of six specimens 
prepared at different times, I find has the composition 

C eo H„ Br 2 0 M = c 20 H„ O e , 2(C 20 II 5 BrO 0 ). 

Purpurine, when treated with bromine in a similar manner, does not yield a 
corresponding compound. 


II. “ On the Magnetic Variations observed at Greenwich.” By Pro¬ 
fessor Wolf of Zurich. Communicated by G. B. Airy, F.R.S., 
Astronomer Boyal. Received December 21, 1863. 

(Translation.) 

In April 1863 Professor Airy kindly communicated to me the Mean 


The Royal Society is collaborating with JSTOR to digitize, preserve, and extend access to 

Proceedings of the Royal Society of London. 

www.jstor.org 








88 Dr* Wolf on the Magnetic Variations at Greenwich . [Jan. 14, 


daily variations of tlie Declination as given by tbe Greenwich Observations 
1841-1857, and as entered in the subjoined Table under v x . 


Calculated by (IV). 

/ 

si 

M O M CO •si-VO oo 

COM *3*0 O to c) VO O O I'-'M ^ V) N M t", VO 

' o o b o b o b o b h o o b o b o o 13* 

1 1 + II 1 1 +++ 1 1 1 ++ 1 1 Vh 


V 

M O oo CO ^no oo O On CO ^ Cl vooo ^ co cl • 

O y}- J^oo voonO p Onno M yf-NO M ON CO l 

*■ onoo t^t^oooo o b O oo oo oo Kvb no vono • 

M M M * 

co co on vo 

O M ON M yo 

boo b bvb 

Calculated by (III). 

/ 

to 

ft 

NONONd'tOCOHOMOOH^tl'tCOH CO 

M OO H VO H O N H OO H N H O O O ON 

- o o *m o o o o o o o h o « o o h m 

H— 1 — 1 —h+H—b+ 1 + 1 1 1 1 1 1 1 b 

w 


s’ 

\ 

COM M OO NO O N ON O ONOO M ^-COM g 

OO yj- O M ON ^ Nt- M o J^m p- onoo yo Jg 

*■ K b K b t^oo on *o O on onoo oo i-^vb no b- ^ 

M m Cp 

NO co M On On 
no yj- yovp on 
do o *o onoo 

M M 

i , i j 
a s 

c+-< 

Jn to d oo yovp oococooONOOd onoo no O 

*-oo dodo do oo on m o *o t^do i^ t^No »o vo cl 

M M M g 


Hourly mean of the Declination. 


h 

12 

12 

20 

12 

20 

20 

18 

20 

20 

20 

21 

9 

II 

II 

II 

20 

IO 

S 


Minimum. 

yi- os yj- o m p p- yn yn yooo yd* O yo jsf-oo oo 
com on co b t^do do b O vo boo do vb m co 

*>MM MVOTf-^-^hCOClMM VO ^ CO 

n wcocoM(!iddt)tltldtldMMMM 

°MMMMMMMMMMMMMMMMM 



^IddddddddddddddddM 


Maximum. 

m p no oo no oo p oo oo yo o p* cono - 3 - 

. d O N O d vooo on b o to to »o io to n ov 
d d m d vovovo- 3 -coddM >o co 

tocococotod d d d MM MMMm mm 
°MMMMMMMMMMMMMMMMM 


Calculated by (II). 

f 

Eta 

ft 

On co O co m vooo O m m no -nJ-oo vo O O m 

yr co co O co on m no to oo on o Mco^-coh co 

^ m m m m *o o Vo o "m o m o o o o m b 10 

1 ++++++ 1 1 1 1 + 1 ++ 1 1 c, 

CO 


s' 

on 0 tN On VO M 0 M m to NO OO VO 0 t+- O : 

yo On CO yo t^Np no Onno p vo ON O ON M O M « 

M 0 O O M b ^■'OVOCOtOd b O O O H 

MMMMWMWMMMMMMMMWM • 

OO VO On o O 

OO Vp ^ vo b 
b vo vo b co 

M M w M M 

Calculated by (I). 

S3 

ft 

MNOt^MO MO tN 0 VO M CONO t^NO On no O 

yo p M On co 0 yj- p 0 NO 00 M ^ M d yt M vo 

- ‘m b *m b b m ‘co b m b m b b b b m b r° 

1 ++++ + + 1 1 1 ! + 1 ++ 1 I 5 

CO 


;T 

«3 

M CO 00 0 OO O M 0 NO M t^NO co CO On NO 2 

vp p yt-vp 00 yo y(- yo co vo boo O O b m m £5 

M M O "o Mb t}- io'io to co b b MO O M 

-MMMMMMMMMMMMMMMMM gf 

O vo t^oo oo 
oo to yj- p M 
b vo io b co 

M M M M H* 

Mean 

absolute 

. 

Vw 

M cono vp M NO OO CO CO On NO O CO CONO O 0 

to h h b to K »o ^ b h to h h b M on 53 

MMMMMM MMMM MMWMM 

m 


Ratios 

r. 

yovp O O O yh yt-vp vo On M t^M on M NO 

On onoo to to b ON o vo b m b b onno b w 

Mm m co o Onno no vo co m d 

M 

ON yJ-Np y}- y}- 

b vb do On 

vo On OnN vo 

Year. 

M M CO ^ vono t>oo On o M d co ^ vono t". 
T'TT'TTTTT'+lOVOVOVOVOlOlOiO 
OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO 
MMMMMMMM^IMMMMMl-tMM 

oo ON O M M 
vo VONO NO NO 

oo oo oo oo oo 

M M M W M 


1 naturally lost no time-in proceeding to try whether 1 could not repre- 








89 


JL864.] Dr. Wolf on the Magnetic Variations at Greenwich , 

sent them from my Sun-spot-ratios r in the same way that I had succeeded 
in doing with those obtained at numerous other stations (see different Nos. 
of my “ Mittheilungen iiber die Sonnenfleeken and I obtained the for¬ 
mula 

^=9^95 + 0*05 6./*. ....... (I) 

The comparison contained in the Table between the observed values and 
the values computed by formula (I) gave me, however, a strikingly less good 
accord than I had obtained for Munich, Prague, Christiania, &e.; and this 
induced me to try how it would be if I formed groups of the years “ rich/’ 
“medium, 55 and “poor” in sun-spots, and compared for each group the 
mean variation with the mean ratio. Thus 


Years. 

Sun-spots. 

Mean. 

Calculated by (II). 

Number. 

- N 

Mean »*. 

*!• 

—s 

Diff. 

1841-1842 

Medium 

24*60 

t 

11*70 

I 1*28 

+0*42 

1841-1844 

Poor ... 

10*80 

1 i*6o 

10*44 

+ 1*16 

1845-1846 

Medium 

40*00 

12*85 

12*22 

+0*63 

1847-1849 

Rich ... 

91*80 

15*80 

1538 

+0*42 

1850-1852 

Medium 

59-53 

12*50 

13*41 

— 0*91 

1853-1854 

Medium 

28-45 

11*30 

11*52 

| —0*22 

1855-1857 

Poor ... 

10*90 

9*43 

10*44 

— 1*01 




Sum of squares 

3*9919 


And I then obtained the formula 

^=9'* 78+ (H)61.r,.. . (II) 

the comparison of which with the values derived from the observations 
shows a much better accord, without the individual years being much 
worse represented than by (I). It follows that the Greenwich observations 
also give on the whole a march corresponding to that of the sun-spots* but 
at the same time with materially greater deviations than appear in the con¬ 
tinental stations which I have previously treated. 

When I communicated to Professor Airy the unexpected result of my 
calculations, he called my attention to the circumstance that his varia¬ 
tions were absolute ones, i. e . the means of the differences between the 
daily extremes, while the variations at other stations which I had employed 
were probably obtained from observations at definite hours; and on my in¬ 
forming him that such was really the case, he gave me in addition the 
Means of the Declinations which corresponded at Greenwich to the pre¬ 
scribed hours of Gottingen time. It is from these subsequently commu¬ 
nicated values that I have derived the maxima and minima and their 
differences entered in the Table under v 2 . The calculation of the quan¬ 
tities in v 2 then led me to make the formula 

^= 6 ^* 67 + 0 * 039 . 7 *; .... 


. . (Ill) 







90 


Mr. 11. J. Lee on the Pneumogastric and [Jan. 21, 

and the comparison in the Table of the values computed by this formula 
with those derived from the observations does in fact show a much greater 
accord. I was, however, further led to infer that the constants in the for¬ 
mula, which I had perceived to vary slowly with the lapse of time at other 
stations, must at Greenwich also have changed materially in the 1 7 years 
(1841-1857), and thus I was finally led to construct the formula 

z? 2 =6*66—0'123(£—1849) + [0*038—0*001 (£—-1849)] .r, (IV) 
which, as the Table shows, suits very well with the observations. For 
application to longer periods it will still require some further modifica¬ 
tion, and, in particular, to be augmented by corrections from the term 
(t— 1849) 2 . In conclusion, I also computed the variations for the years 
1858-1862 by all the four formulae, and have entered them in the Table 
for future comparison. 


January 21, 1864. 

Major-General SABINE, President, in the Chair. 

The following communications were read :— 

I. “ A Description of the Pneumogastric and Great Sympathetic 
Nerves in an Acephalous Foetus.” By Robert James Lee, 
Esq., B.A, Cantab. Communicated by Robert Lee, M.D. 
Received November 20, 1863. With Supplement, received 
J anuary 20,1864. 

(Abstract.) 

The author observes that hitherto no account has been given of the 
origin and distribution of the par vagum or pneumogastric nerve in any 
instance of a foetus born with brain entirely or partially wanting. This 
reason has been thought sufficient for communicating to the Royal Society 
the description of a dissection of the pneumogastric and sympathetic nerves 
in a foetus born at the full period, in which the cerebellum and medulla 
oblongata were absent. At the time of birth it cried, moved, and for the 
space of one hour might be said to live. All the thoracic and abdominal 
viscera were found properly formed, and the upper and lower extremities 
properly developed. The eyes, nose, and mouth were present. The head, 
when regarded as a whole, seemed as though the posterior and superior 
parts had been entirely removed, thus leaving the spinal cord and base of 
the skull exposed. Some tough cerebral matter, covered only by a dense 
membrane, was seen in two small masses exposed in the cranium, not con¬ 
tinuous with the spinal cord (which terminated abruptly at the base of the 
cranium and was entirely exposed at this point), but separated from it by a 
bony prominence arising from the floor of the cranial cavity. 

After the removal of the extremities, the abdomen was opened and the 
viscera of the abdominal cavity removed. The anterior halves of the ribs 



