He boiled the needles of the arbor vitae tree (eastern white cedar) to make a tea that was later shown to contain 50 mg of vitamin C per 100 grams. Such treatments were not available aboard ship, where the disease was most common. In February 1601, Captain James Lancaster, while sailing to Sumatra, landed on the northern coast of Madagascar specifically to obtain lemons and oranges for his crew to stop scurvy. Captain Lancaster conducted an experiment using four ships under his command. One ships crew received routine doses of lemon juice while the other three ships did not receive any such treatment. As a result, members of the non-treated ships started to contract scurvy, with many dying as a result.During the Age of Exploration (between 1500 and 1800), it has been estimated that scurvy killed at least two million sailors. Jonathan Lamb wrote: "In 1499, Vasco da Gama lost 116 of his crew of 170; In 1520, Magellan lost 208 out of 230;...all mainly to scurvy. "In 1579, the Spanish friar and physician Agustin Farfán published a book in which he recommended oranges and lemons for scurvy, a remedy that was already known in the Spanish Navy.In 1593, Admiral Sir Richard Hawkins advocated drinking orange and lemon juice as a means of preventing scurvy.In 1614, John Woodall, Surgeon General of the East India Company, published The Surgions Mate as a handbook for apprentice surgeons aboard the companys ships.
Dysgraphia is a learning disability of written expression, that affects the ability to write, primarily handwriting, but also coherence. It is a specific learning disability (SLD) as well as a transcription disability, meaning that it is a writing disorder associated with impaired handwriting, orthographic coding and finger sequencing (the movement of muscles required to write). It often overlaps with other learning disabilities and neurodevelopmental disorders such as speech impairment, attention deficit hyperactivity disorder (ADHD) or developmental coordination disorder (DCD).In the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), dysgraphia is characterized as a learning disability in the category of written expression, when ones writing skills are below those expected given a persons age measured through intelligence and age-appropriate education. The DSM is unclear in whether writing refers only to the motor skills involved in writing, or if it also includes orthographic skills and spelling.Dysgraphia should be distinguished from agraphia (sometimes called acquired dysgraphia), which is an acquired loss of the ability to write resulting from brain injury, progressive illness, or a stroke.The prevalence of dysgraphia throughout the world is not known, due to difficulties in diagnosis and lack of research. Etymology
The word dysgraphia comes from the Greek words dys meaning "impaired" and γραφία graphía meaning "writing by hand". Development
There are at least two stages in the act of writing: the linguistic stage and the motor-expressive-praxic stage. The linguistic stage involves the encoding of auditory and visual information into symbols for letters and written words.