464 
PHARMACEUTICAL SOCIETY, EDINBURGH. 
A Meeting was held in St. George’s Hall on Tuesday evening, 11th January ; Mr. 
Aitken, President, in the chair. 
After a few introductory remarks, in which it was stated that the London President, 
Mr. II. S. Evans, was present, the following communication was made:—“On the Re¬ 
cent Investigation on the Action of Chloral,” by Dr. Arthur Gamgee, F.R.S.E., Lec¬ 
turer on Physiology at Surgeons’ Hall, and Physician to the Edinburgh Royal Hospital 
for Sick Children. 
Mr. President and Gentlemen,—Only a few months have elapsed since the time 
when I had the pleasure of bringing before your notice the results of researches on the 
action of certain poisons on the blood. These researches, you will remember, showed 
how, thanks to the recent strides in the science of chemistry, no less than in the study 
of physiology, great progress is being made in the elucidation of the exact mode 
of action of various poisonous and medicinal substances. The introduction of hydrate 
of chloral into medicine will afford another illustration of the advantages which 
the healing art is likely to derive from discoveries of chemistry, and the introduc¬ 
tion of new bodies discovered by its aid to the treatment of disease. But for this 
science the anaesthetics which we daily employ would be unknown to us, and hu¬ 
manity would be deprived of the inestimable benefits which result from their use in the 
alleviation of the sufferings which necessarily accompany the use of essential remedial 
measures. That medicine has much to expect yet from chemistry has only been re¬ 
cently proved. In the iodide of methyl-strychnium w'e have had lately demonstrated 
to us how a powerful tetanic poison may be so modified by a chemical operation as 
to yield a substance having almost exactly opposite action,—an action identical with 
that of Woorari, the curious American arrow-poison. In the discovery of apomorphia 
by Dr. Matthiessen we have another instance of the possibility of getting from sub¬ 
stances already known to us others possessed of great energy, and endowed with new 
and important actions, for from the narcotic alkaloid morphia a base has been ob¬ 
tained, whose chief and most marked action it is to produce vomiting. The hydrate 
of chloral, the, I might almost say, sensational drug of the present day, was, like chloro¬ 
form, only known as a chemical curiosity until physiological investigation showed it 
to be possessed of properties likely to prove valuable. 
Relations of Chloral to other Bodies. —Let me first remind you of the formula of 
alcohol, C 2 H 6 0. This body, as you know, when treated with certain oxidizing agents, 
yields a substance called aldehyde, a colourless liquid of snffocating smell, miscible in 
all proportions with water, and well known for its power of reducing solutions of 
nitrate of silver. This body has the formula C 2 H 3 0. j 
Now, by acting for a long time—about seventy hours—upon alcohol by means of 
chlorine, we obtain a body which appears to differ from it in having hydrogen replaced 
by Cl, having therefore the chemical formula C 2 H C1 3 0, and represented by the for¬ 
mula C 2 C1 3 0.1 
Hi 
Properties of Chloral. —This body exists in a liquid condition, possessing a powerfully 
pungent odour. Its specific gravity is 1500, and its boiling-point is very nearly the 
same as that of water, being 99° C., or 210° F. Chloral has a great tendency to com¬ 
bine with water, and forms a white crystalline solid body—the hydrate of chloral, which 
I have to bring under your notice. This hydrate is very soluble in water. It is vola¬ 
tilized by heat, and may be purified in this manner. 
Decomposition with Alkalies. —It has long been known that when treated with caustic 
alkalies chloroform is developed, and at the same time there is formed a formiate of the 
alkali. 
This decomposition is interesting to us, as a knowledge of it led Liebreich to spe¬ 
culate that chloral might be a valuable remedy. The blood being an alkaline fluid, was, 
he supposed, likely to effect the decomposition of chloral, and to cause a gradual evolu¬ 
tion of chloroform throughout the economy. To a certain extent facts appeared to 
countenance the hypothesis, for chloral was found to produce, when introduced into the 
system of animals, a more or less deep sleep lasting for hours, which, unless the dose 
had been excessive, passed off without leaving any serious symptoms. For a descrip- 
