1901] MICROSCOPICAL JOURNAL 153 
as to the method of manufacture, and shows that wide va- 
riations in character often exists. These differences, when 
they occur, are readily distinguishable by the microscope 
and, in most every case, it is, by this means, possible to 
conclude, of two test samples, whether they could or could 
not have come from the same source ; and this is true, un- 
der favorable conditions, even if one of the samples has 
been subjected, for some time,to the action of the stomach.” 
The work of Professor Dana is well known, but at first 
I had only at command the limited notice given to it in 
SUSPECTED SAMPLE No.2. x75. 
the works on toxicology. Later I received the article of 
Professor Dana, which he kindly sent me, and was inter- 
ested in carrying out more in detail the methods of work 
which he describes. My method of work was as follows: 
I mounted a few slides of each of the samples (the lim- 
ited amount of crystals separated from the whiskey made 
but one slide) as well as samples of white arsenic from 
the laboratories of the university and from the drug stores 
of the eity. Differences were so marked that I at once 
concluded that the sample submitted by the county at- 
