32 Orobanche Virginiana. 
banche has been supposed by many persons, to have formed a part 
of the celebrated cancer-powder of Dr. Hugh Martin, whose success 
«« Anxious to discover a medicine that promised relief in even a few cases of cancers, 
and supposing that all the caustic vegetables were nearly alike, I applied the phyto- 
lacca or poke root, the stramonium, the arum, and one or two others, to foul ulcers, 
in hopes of seeing the same effects from them which I had seen from Dr. Martin’s 
powder ; but in these I was disappointed. They gave some pain, but performed no 
cures, At length I was furnished by a gentleman from Fort Pitt with a powder which 
I had no doubt, from a variety of circumstances, was of the same kind as that used by 
Dr. Martin. I applied it to a fungous ulcer, but without producing the degrees of 
pain, inflammation, or discharge, which I had been accustomed to see from the appli- 
cation of Dr. Martin’s powder. After this, I should have suspected that the powder 
was not a simple root, had not the doctor continued upon all occasions to assure me 
that it was wholly a vegetable preparation. 
> 
«* In the beginning of the year 1784 the doctor died, and it was generally believed that 
his medicine had died with him. A few weeks after his death, I procured from Mr. 
Thomas Leiper, one of his administrators, a few ounces of the doctor’s powder, partly 
with a view of applying it to a cancerous sore which then offered, and partly with a 
view of examining it more minutely than I had been able to do during the doctor’s 
life. Upon throwing the powder, which was of a brown colour, upon a piece of white 
paper, I perceived distinctly a number of white particles scattered through it. I sus- 
pected at first that they were corrosive sublimate; but the usual tests of that metallic 
salt soon convinced me that I was mistaken. Recollecting that arsenic was the basis 
of most of the celebrated cancer-powders that have been used in the world, I had re- 
course to the tests for detecting it. Upon sprinkling a small quantity of the powder 
upon some coals of fire, it emitted the garlic smell so perceptibly as to be known by 
