﻿OF THE STATE ENTOMOLOGIST. 11 



Adolph Kayser, and reported in a paper entitled ''Are Potato Bugs 

 poisonous?" read before the American Association for the Advance- 

 ment of Science at its meeting in Detroit. The following extracts 

 give the substance of the paper: 



To investigate the mutter, a quantity of the buffs collectefl from fields near- 

 Buffalo, where no arsenic had been used, was subn)irted to distillation with salt 

 water, so as to allow of an increased temperature. Under this process, about four 

 ounces of liquid wrre procured from one quart measure of the insect*. This liquid was 

 perfectly clear, and emitted a highly offen.vive smell ; it proved of alkaline reaction on 

 account of the presence of a certain quantity of free ammonia and carbonate of ara-^ 

 monia. 



Again, an equal quantity of the bugs was used to prepare a tincture madi; as fol- 

 lows :— Absolute and cht^inieaily pure alcohol was condensed upon the live bugs ; after 

 a digestion of twentv-four hours the alcohol was evaporated at a gentle heat. The 

 tincture so obtained had a decidedly acid reaction, was brown in color, and was not 

 disagreable in stnell. 



To ascertain th^^ eff^-ct on the animal system of the liquid and the tincture above 

 described, a number ot frogs were procured for the experimtnt. About one half cubi& 

 centimeter of the liqiud and the tincture each was introduced separately into the 

 stomach. Neither the liqtiid nor the tincture produced any apparent eftects. The viva- 

 city of the frosrs so tn-ated continued unim paired, notwithstanding the complete reten- 

 tion of the doses. Agaui two fresh frogs were submitted to a hypodermic injection of 

 the liquid and the tincture, in the hind legs, by means of an ordiniry hypodermic 

 syringe. The injection of the distilled liquid was unattended by injurious results. 

 A slight disinclination, at first, to use the hind limbs was shown also in the case of an- 

 other frog, which was treated hypodermically with pure water to check the results ob- 

 tained. 



The injection of the tincture, however, proved fatal to the subject. A few 

 moments alter the inj- ction 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. 



The tincture though highly concentrated, contained but a small quantity of animal 

 acids. * * * Tiie acids beinir found to be present in such small quantity, the con- 

 clusion is unavoidable, in the light of the present experiments, that the bugs are not 

 poisonous. 



The experimenters conclude that the reported cases of poison- 

 ing result rather from the arsenic used in destroying the insects, or 

 from carbonous oxide produced by incomplete combustion when large 

 amounts of the beetles are thrown into a fire. It Is to be hoped that 

 the experiinents will be continued, 1st, because they by no means 

 cover the whole ground ; 2nd, because, so far, they admit of the oppo- 

 site conclusion to which the experimenters arrived. Until we have 

 learned what the active principle is which produces the physiological 

 effect that has been well attested, and the precise conditions under 

 which it acts, the experience recorded in my last report will go for 

 more than such experiments. The active principle, as there stated, is 

 most probably volatile, and the processes described in the above ex- 

 periments very probably had the effect to liberate the poison. Boil- 

 ing is well known to destroy many organic poisons in this manner or 

 by decomposition, and the green tuber, the fruit and haulm of the 

 common potato lose their poisonous qualities by being so treated. In 

 obtaining tinctures, whether by percolation of the powdered material, 

 or as described in the experiments, the poisonous principle may^ 



