and its Alkaloid Conia. 389 
bath till the residue had the consistence of syrup, and subjecting 
this extract, in a proper distilling apparatus, with its own weight 
of water and a little caustic potassa, to the heat of a concentrated 
boiling solution of muriate of lime. The conia passes over readily 
with the water, floating on its surface and quite colourless. 
In the proximate analysis of organic substances, it is of primary 
consequence that the agents employed be such as will accomplish 
simple separation of the proximate principles from each other, 
without producing new compounds by a new arrangement of ele- 
ments. Some chemists have entertained doubts whether even 
any of the methods of analysis at present in use fulfil correctly 
this condition. But all are agreed in thinking that the agency 
of strong acids or strong alkaline solutions, more especially when 
concurring with an elevated temperature, should in general be 
avoided, as tending rather to form new compounds, than simply 
to detach compounds already formed by nature. Hence a ques- 
tion may justly arise, whether the substance I have been de- 
scribing is the real active principle of hemlock, or a new product 
formed by the action of caustic potassa aided by heat ? 
Here it may be observed, in the first instance, that heat is not 
necessary for the development of conia in hemlock and its pre- 
parations ; for its peculiar odour is at once disengaged from the 
powder of the seeds when treated with solution of potassa at or- 
dinary atmospheric temperatures, 
By far the most direct and satisfactory test, however, of the 
force of the above objection in such circumstances, is the effect 
of the detached principle on the animal body, and the relation the 
phenomena bear to those produced by the crude substance from 
which the principle is obtained. In the present ‘case experiment 
amply proves, that the conia of Gererr concentrates in itself the 
properties of hemlock,—and, if not itself the true active principle, 
must contain it in large quantity. 
The researches of GercEr on this head are few in number, and 
were chiefly confined to small birds as the subject of experiment. 
3D2 
