454 
ON TESTING EOR ANTIMONY AND ARSENIC. 
By Henry Hough Watson, Esq. 
Owing to the extreme facility there is in applying Reinsch’s 
process, and the great delicacy of it in separating arsenic and 
antimony from organic matter containing them, it has, of late 
years, generally been resorted to by chemists and toxicolo- 
gists, almost entirely to the neglect of Marshes process, in 
investigating the numerous cases of poisoning by arsenic 
which have occurred; and there has been no difficulty in 
proving the metal deposited upon the copper to be arsenic, 
when the coated copper was heated in a subliming tube (the 
arsenic being thereby oxidized and converted into arsenious 
acid), and when, afterwards, the ammoniacal nitrate of silver, 
the ammoniacal sulphate of copper, and the sulphuretted 
hydrogen tests were applied ; but, as till within the last year, 
attention had not been directed to cases of criminal poisoning 
by antimony, equally easy and direct means were not known 
of proving, by indubitable results, that a coating or deposit 
obtained on copper was antimony. Dr. Odling has, however, 
in the last volume of c Guy’s Hospital Reports/ (vol. ii, third 
series), described a method, discovered by him, of oxidizing 
and bringing into solution a deposit of antimony, in such 
manner that all the striking and decided characteristics of 
this metal can be readily and satisfactorily elicited ; and per- 
haps every chemist, wffiose attention has been drawn to 
Dr. Odling’s paper, will admire and highly appreciate his 
process ; but, it may be questionable whether any can 
so completely prize it as those who have had cases of poi- 
soning by antimony to investigate both before and since its 
publication. I am one of the few who have had to detect and 
prove the presence of absorbed antimony in the tissues in 
case of poisoning before and since the publication of the 
paper ; and I feel that I cannot too freely acknowledge the 
superior value of the aid rendered by the process over the 
other more complex means I had to adopt previously. Yet, 
though beautifully simple and eligible, as Dr. Odling’s pro- 
cess is, consideration of the principle on which it is founded 
has led me to the discovery of another method, at least 
equally simple, and, I think, generally, even more eligible, 
except, perhaps, when the deposit is so thick as to crack off 
the copper. But, before explaining, it may be well to con- 
trast the position we were in up to the time when the last 
