108 
ON CHLOROFORM. 
purified it fully, and made an accurate analysis of it : he found it 
to be composed of twelve parts carbon, one part hydrogen, and LOG^ 
parts chlorine, and named it chloroform, from being analogous to 
formic acid in its composition, but containing chlorine instead of oxy- 
gen. From theoretical considerations Liebig termed it perchloride 
or terchloride of formyle, — in chemical symbols, C 2 H Cl 3 . It is 
a colourless, transparent liquid, of specific gravity nearly 1500, or 
about 1| times the weight of water; it boils at 141° Fahr., the 
vapour having a specific gravity nearly four times that of air ; it 
quickly evaporates at ordinary temperatures, but does not burn 
easily ; it has a sweet taste and agreeable smell ; is soluble in all 
proportions in strong spirit, but very sparingly soluble in water, to 
which it communicates its taste in a small degree. 
To the best of my knowledge, from the result of many inquiries, 
it seems to have been introduced into this country as a medicinal 
agent, first in Liverpool, where, indeed, in the form of a spirituous 
solution, it has been more known than in any other part of the 
country, and from which, I believe, the knowledge of its therapeutic 
properties has extended. About the year 1838 or 1839, a prescrip- 
tion was brought to the Apothecaries’ Hall, Colquitt-street, one 
ingredient of which was chloric ether. No substance being known 
there of that name having the properties of that with which the 
mixture had been previously prepared, Dr. Brett, then the com- 
pany’s chemist, in investigating the subject, found, in the United 
States Dispensatory, the formula for its preparation which has been 
noticed above, and prepared some. Its properties pleased some of 
the medical men, particularly Dr. Formby, by whom it was intro- 
duced into practice in this town. After coming to take charge of 
the company’s laboratories, I found that the method of preparation 
yielded a product which was not of uniform strength, and some- 
times of disagreeable flavour. Accordingly, I altered the process, 
by separating and purifying the chloroform, and dissolving it in 
pure spirit, by which a product of uniform strength and sweet 
flavour was always obtained. Thus prepared, it is much superior 
to specimens I have seen of London manufacture. Those members 
of the profession who are in the habit of using it prefer it greatly 
to sulphuric ether, as possessing all its remedial value, and being 
verv much more agreeable. 
The vapour of the so-called chloric ether seems to have been 
tried as a substitute for sulphuric ether in February or March 
last, but without very satisfactory results, which, indeed, could 
scarcely be expected, unless the vapour of alcohol possessed the 
same properties, it being composed principally of alcohol. When 
in Scotland, in October last, Dr. Simpson introduced the subject 
to me, inquiring if I knew of anything likely to answer. Chloric 
