last Half-Century. 
1883.] 
5^1 
let us take up the first question, and reply with an em- 
phatic “ No !” 
Aconitine is an instance in point. We may judge that it 
has been taken by the symptoms which it produces, and by 
physiological tests which the operator applies to himself or 
to other animals. But true chemical reactions, precise and 
available, it does not exhibit. We may extract it from the 
remains of the deceased, and obtain it, freed from all other 
substances, in a state of purity ; but when this is done we 
cannot give a chemical or physical faCt in answer to the 
question, “ How do you know that this particle of matter 
which you produce in the watch-glass is aconitine ? ” The 
microscope, the spectroscope, the polariscope, which have 
solved so many problems, are here silent. Colour-tests 
have been proposed, but a doubt hangs over them all, and 
in some cases the reaction described would seem due not to 
the aconitine itself, but to some impurity, which may or 
may not be present. Hence they are of no scientific value. 
We may next turn to the ptomaines. Recent researches 
have made known the existence of a class of alkaloids or 
organic bases which are generated in the body during putre- 
faction, during morbid conditions prior to death, and even, 
it is said, during normal healthy life. Concerning these 
cadaveric alkaloids we know, as yet, sadly little. We can- 
not state their number, nor lay down their physiological 
action, the circumstances under which they originate, and 
the reactions by which they may be recognised. Some of 
them resemble strychnine in their aCtion upon the human 
system, and in certain of their chemical reactions. Indeed, 
in the work before us, mention is made of a case where an 
Italian toxicologist, F. Ciotto, pronounced strychnine to be 
present in a dead body, whilst Prof. Salmi, one of the chief 
investigators of the ptomaines, being called for the defence, 
showed that the substance in question differed in some of 
its properties from strychnine, and was probably one of the 
ptomaines. Some time ago it was asserted that the 
ptomaines might, as a class, be readily distinguished from 
the natural vegetable bases by their property of reducing 
potassium ferri-cyanide to ferro-cyanide, and thus giving a 
blue precipitate with ferric salts. But some of the vegetable 
bases — among others aconitine — produce the very same re- 
action, though more slowly. Hence the class distinction is 
broken down, and all that can be done is, as the authors of 
the work before us suggest, to depend upon the faCt that 
there is no ptomaine known which produces all the charac- 
teristic reactions of morphine, aconitine, &c. But this is 
VOL. V. (THIRD SERIES.) 2 M 
