BRITISH ASSOCIATION FOR ADVANCEMENT OF SCIENCE. 533 
of Strychnia in certain cases. A new Method of Instituting 
post-mortem Researches for Strychnia. 
By Mr. T. Horsley. 
In the first lecture Mr. Horsley observed that the circum- 
stances attending Palmer’s trial induced him to make a series 
of experiments on the subject, and he tried the effects of a 
precipitant, formed of one part of bichromate of potash, 
dissolved in fourteen parts of water, to which was afterwards 
added two parts in bulk of strong sulphuric acid. This 
being tried upon a solution of strychnine, the agent was en- 
tirely precipitated in the form of a beautiful golden-coloured 
and insoluble chromate. The experiment, as performed by 
Mr. Horsley, was very interesting, and scarcely a trace of 
bitterness was left in the filtered liquor. He did not claim 
to have originated this discovery of the use of a chromic salt 
and an acid liquor ; but the point to which he called attention 
was the essential difference in the mode of application, and 
he maintained that it was as much out of the power of any 
human being to define the limit of sensibility which he had 
attained, as it would be to count the sands or to measure the 
drops of the ocean. Taking thirty drops of a solution of 
strychnia containing half a grain, he diluted it with four 
drachms of w^ater. He then dropped in six drops of a solution 
of bichromate of potash, when crystals immediately formed, 
and decomposition w 7 as complete. Splitting up the half grain 
of strychnia into millions of atoms of minute crystals, he said 
that each of these atoms, if they could be separated, would 
as effectually demonstrate the chemical characteristics of 
strychnia as though he had operated with a pound weight of 
the same. He then showed the chemical reaction with those 
crystals. Dropping a drop of liquor containing the chromate 
of strychnia into an evaporating dish and shaking it together, 
he added a drop or two of strong sulphuric acid, and show r ed 
the effect as previously noted. He next showed the dis- 
coloration produced in chromate of strychnia and chromate 
of brucia by sulphuric acid, the former being changed to a 
deep purple and then to a violet and red. It had been as- 
serted since the trial of Palmer that the non-detection of 
strychnine in the body of John Parsons Cook was owing to 
the antimony taken by the deceased having somewhat inter- 
fered with the tests. Such a supposition was, in his (Mr. 
Horsley’s) opinion, absurd. Nothing, he considered, could 
more incontestably disprove the fallacy than either of two 
new tests which he then performed. These he considered 
