72 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 9 



found, however, that most of the essential oils would injure plants 

 when applied to them and when put on animals, the relief obtained from 

 even the best was dependent upon the abundance and the hunger of 

 the attacking insects. Several oils are valuable against mosquitos, 

 but if in a locality where mosquitos are extremely abundant and very 

 hungry, the results are not so good. 



Toxicity of Nitrobenzene 

 The next group of compounds to be studied was the benzene series 

 and the compound selected for the first week was nitrobenzene. It 

 was found that one drop of nitrobenzene placed on a piece of filter 

 paper and allowed to evaporate under a bell-jar containing approxi- 

 mately one cubic foot of air, would destroy the adult white fly on a 

 plant in about one hour to one and a half hours. In looking through 

 the literature to ascertain the toxicity of nitrobenzene, it was found 

 that nitrobenzene is considered to be a very serious poison. Blyth^ 

 mentions a number of experiments showing that nitrobenzene is ex- 

 tremely poisonous. One experiment cited was that in which a cat was 

 exposed under a glass shade in which 15 grams of nitrobenzene were 

 evaporated on warm sand. The animal immediately showed symp- 

 toms of poisoning. After thirty minutes' exposure, when the shade 

 was removed to introduce another 15 grams, the cat for a moment 

 escaped, but was recaptured and replaced under the shade and in one 

 hour and forty minutes was dead. He also cites the case of a nmn who 

 died from the effects of nitrobenzene which had been spilt upon his 

 clothes, to show that the vapor of nitrobenzene is poisonous. Filehne- 

 cites a case in which he placed a rabbit in a large glass bottle into 

 which he led strong nitrobenzene vapor. In a half-hour, the animal 

 was no longer normal in appearance and in forty minutes was lying 

 upon its side. He states that if the animal is then removed, in from 

 a half-hour to two hours, it will return to its normal condition. If, 

 however, it is not removed, the animal will die. Haines^ states that 

 nitrobenzene is poisonous when taken internally, when inhaled as a 

 vapor, or when absorbed by the skin. He even stated that symptoms 

 of poisoning may result from the use of almond glycerine soap, which 

 contains nitrobenzene, particularly when used in hot water. Holland* 

 states that nitrobenzene breaks down the blood corpuscles forming 

 methemoglobin and paralyzes the nerve centers, the immediate symp- 



iBlyth, Poisons and Their Effects and Detection, third ed., p. 184. 

 ^Filehne, Ueber die Giftwirkungen des Nitrobenzol Archiv fur Experimentelle 

 Pathologic and Pharmakologie, Vol. 9, 1878, p. 342. 



'Peterson & Haines, Textbook of Legal Medicine and Toxicology, p. 606. 

 * Holland, Medical Chemistry and Toxicology, 1915, p. 438. 



