VETERINARIAN. 
VOL. XXX, tttt v l Fourth Scries, 
No. 355. 180/. No. 31. 
Communications and Cases. 
ON THE VEGETABLE ALKALOIDS. 
It is not saying too much to assert that modern chemistry, 
in devising means to abstract from vegetables their active 
principles, has materially contributed to the science of medicine, 
by furnishing therapeutic agents on which reliance can always 
be placed, arising from the uniformity of their composition. 
Naturally these principles exist as saline compounds, con- 
sisting of an acid and an alkaline base, to’ which latter the term 
alkaloid has been applied. This salifiable base has been 
isolated by the chemist, and found to possess the leading 
characters of an alkali, namely, that of restoring the blue 
colour to reddened litmus, and neutralizing acids. But what 
more especially distinguishes these bodies is, they contain 
nitrogen as one of their constituents. Besides which, the 
usual elements of organic substances, carbon, hydrogen and 
oxygen, are also present ; and the equivalent number is 
always very high. They have likewise a bitter taste, and are 
but sparingly soluble in water, but more soluble in alcohol, 
and readily so in the diluted acids; the compounds thus 
formed being decomposed by the true alkalies. Professor 
Graham considers ammonia to be a type of them. 
From the analogy that obtains among these principles a 
general method for the separation of the base is applicable to 
nearly all of them. This essentially consists in boiling the 
vegetable substance in acidulated w r ater, filtering and neu- 
tralizing either by ammonia, lime, or magnesia, when the 
alkaloid is precipitated ; after which it is purified. Benzole, 
or the bicarburet of hydrogen of Faraday, obtained by the 
compression of oil gas, has been lately employed for this 
purpose. It is a clear, volatile liquid, having the odour of 
xxx. 49 
