122 ON THE CHEMICAL EFFECTS OF CHLORAL HYDRATE; ETC. 
of one important chemical agent, which has only lately been 
brought before the notice of the medical profession, both 
here and at home, or rather in Europe. I mean chloral, or, 
as its more chemical name is supposed to be, “ Trichloric 
Aldehyde.” This substance is now in use as a hydrate, and 
its action has been stated to be somewhat like chloroform. 
When an alkaline solution is added to it, chloroform is set 
free; hence its proposer, Liebreich, suggested its use: that 
meeting with alkaline elements in the blood, it might become 
decomposed into chloroform. This theory, which is a very 
taking one, was, no doubt, the cause of the experimental use 
of this substance. The general experience, however, of the 
profession is against the idea that it acts as an anaesthetic, but 
only as a true hypnotic. 
I feel inclined to the opinion that, though it appears almost 
certain that chloroform is eliminated in the blood by its de¬ 
composition, yet that the action of that agent is considerably 
modified by the attendant chemical change which necessarily 
accompanies the decomposition of this agent in the blood. If 
it is correct that the hydrate of chloral is decomposed by the 
alkaline state of the blood, then it follows as certainly that 
the resulting compounds must be chloroform and a formate of 
some alkali. And if we regard the presence of alkalinity to 
be normal in the blood, then we obtain not only the chemical 
or physiological action of chloroform, but we have also to 
consider what may be the physiological effect of the formate 
of an alkali, whether of ammonia or potassa, and on such 
grounds we may fairly deduce that the physiological effects of 
chloral on the animal economy must be somewhat different 
to that of chloroform by itself; hence, perhaps, hypnotism, 
in place of anaesthesia.* 
At the risk of being tedious, I now approach the demon¬ 
stration I have proposed to make, by reference to the line of 
my owrn experience in this matter; and I extract the fol- 
* The decomposition of chloral hydrate by ammonia is curious to witness 
when carried out in the following manner:—A solution of the hydrate 
should be placed in a narrow tube, about seven or eight inches long, and 
ammonia added, and the mixture shaken and slightly warmed, wdien a white 
cloudiness wiil make its appearance, and bubbles of gas rise to the surface. 
If now a little superstratum of water is added, and not allowed to mix 
with the contents of the tube, the bubbles of gas will be seen passing 
through this stratum of water, and with a pocket lens the decomposition 
will be well seen. So soon as a bubble reaches the surface and disappears, 
from that point there descends an oily looking fluid (chloroform); but be¬ 
fore this reaches the cloudy portion, an amorphous or semi-crystalline 
material is formed—formate of ammonia; what the gaseous portion is I 
have not ascertained. 
