242 ANNUAL OF SCIENTIFIC DISCOVERT. 



I was able, in a most positive manner, to determine the presence of 

 nicotine in the blood. I was able to determine its physical characters, 

 its odor, taste, and alkalinity. I succeeded in obtaining the chloro- 

 platinate of the base perfectly crystallized in quadrilateral rhomboidal 

 prisms of a rather dark yellow color, and to ascertain their insolubility 

 in alcohol and ether. 



I have applied the same process to the detection of coniine in a 

 very old tincture of hemlock, and I was equally successful in extract- 

 ing from the liquid colorless coniine, presenting all the physical and 

 chemical properties of this alkaloid. I was also able to prove that the 

 ether which holds coniine in solution, carries off a notable portion of 

 this alkaloid, when the solvent is exposed to spontaneous evaporation. 



Examination for a Solid and Fixed Alkaloid. Let us now suppose 

 that the alkaloid is solid and fixed ; in that case, according to the 

 nature of the alkaloid, it may happen that the evaporation of the ether 

 resulting from the treatment of the acid matter, to which we have 

 added bicarbonate of soda, may leave or not a residue containing an 

 alkaloid. If it does, we add a solution of caustic potash or soda to 

 the liquid, and agitate it briskly with ether. This dissolves the vege- 

 table alkaloid, now free, and remaining in the solution of potash or 

 soda. In either case, we exhaust the matter with ether. Whatever 

 be the agent which has set the alkaloid free, whether it be the bicar- 

 bonate of soda or potash, or caustic soda or potash, it remains, by the 

 evaporation of the ether, on the side of the capsule as a solid body, 

 but more commonly as a colorless milky liquid, holding solid matters 

 in suspension. The odor of the substance is animal, disagreeable, but 

 not pungent. It turns litmus paper permanently blue. 



When we thus discover a solid alkaloid, the first thing to do is to 

 try and obtain it in a crystalline state, so as to be able to determine 

 its form. Put some drops of alcohol in the capsule with the alkaloid, 

 and leave the solution to spontaneous evaporation. It is, however, 

 very rare that the alkaloid obtained by the above process, is pure 

 enough to crystallize. Almost always it is contaminated with foreign 

 matters. To isolate these substances, some drops of water, feebly 

 acidulated with sulphuric acid, are poured into the capsule, and then 

 moved over its surface, so as to bring it in contact with the matter in 

 the capsule. Generally we observe that the acid water does not 

 moisten the sides of the vessel. The matter which is contained in it 

 separates into two parts ; one formed of greasy matter which remains 

 adherent to the sides ; the other alkaline, which dissolves and forms 

 an acid sulphate. We cautiously decant the acid liquid, which ought 

 to be limpid and colorless, if the process has been well executed ; the 

 capsule is well washed, with some drops of acidulated water, added 

 to the first liquid, and the whole is evaporated to three-fourths in 

 vacuo, or under a bell jar over sulphuric acid. We put into the 

 residue a very concentrated solution of pure carbonate of potash, and 

 treat the whole liquid with absolute alcohol. This dissolves the 

 alkaloid, while it leaves untouched the sulphate of potash, and excess 

 of carbonate of potash. The evaporation of the alcoholic solution 



