206 Are Potato Bugs Poisonous ? [ April, 
fresh frogs were submitted to a hypodermic injection of the liquid 
and the tincture, in the hind legs, by means of an ordinary hy- 
podermic syringe. The injection of the distilled liquid was unat- 
tended by injurious results. A slight disinclination, at first, to 
use the hind limbs was shown also in the case of another frog, 
which was treated hypodermically with pure water to check the 
results obtained. 
The injection of the tmeture, however, proved fatal to the sub- 
ject. A few moments after the injection the leg operated upon 
seemed to become paralyzed, and the heart stopped beating 
within thirty minutes afterwards, by which time the other two 
hypodermically treated seemed to have completely overcome the 
effects of the operation. 10 
The tincture, although highly concentrated, contained but a 
small quantity of animal acids, which, when saturated with bases 
of potassa and soda, formed deliquescent hexagonal crystals, visi- 
ble under the microscope, but insufficient in quantity to analyze. 
It is known that such acids are very active in their effects upon 
the animal system. The bite of a flea or of a bedbug is attended 
by an introduction of acids which produce a swelling by the coag- 
ulation of the albuminous fluids of the body. The rapid coagula- 
tion of milk was shown by the experiment of introducing a few 
drops of the tincture above described, during the present experi- 
ments. In the case of the insects above mentioned, especial or- 
gans are occupied with the secretion of the acids which serve the 
insect economy by coagulating those parts of the blood of the 
victim which may not be useful for food. No such organs have 
been noticed in the potato bug. The presence of the acid leads 
us to conjecture as to the origin of such organs, while they have 
apparently not become developed in the potato bug. The acids 
being found to be present in such small quantity, the conclusion 
is unavoidable, in the light of the present experiments, that the 
bugs are not poisonous. 
Rather does it seem likely that the published statements to the 
contrary were based on erroneous observations, while it is eX 
tremely probable that certain of the more aggravated and circum- 
stantially detailed cases of poisoning are due to the effects of ar- 
senic (Paris green and arsenious acid), which is now profusely 
used for the extermination of the bugs. Many metallic salts will 
produce cutaneous irritation ; when arsenic is sublimed by heats 
the inhaled fumes will produce nervous disorder ; the effects of 
Paris green may have been mistaken’ for those of the potato 
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