Biological Papers. 141 



served that alcohol alone (which is the menstruum used in the manu- 

 facture of the fluid extract), would produce practically the same 

 result, although recovery was noted in some cases. Aqueous prep- 

 arations of cimicifuga were ineffective. 



This is interesting, as cimicifuga is well known to be a plant 

 which insects invariably shun in the open field, and hence its 

 name — "cimic," a bug, and "fuga," to fly. This word was sug- 

 gested by the peculiar property of the plant, which was in early 

 times thought to be an insecticide. 



The commercial insecticide above mentioned was tried in the 

 same manner. By contact method in open jar it killed almost in- 

 stantly. As a fumigant it had one- fiftieth of the toxic power of 

 sulphur. This preparation, having the trade name of "Vermingo," 

 is said to contain 6| per cent of carbolic acid, among other ingre- 

 dients. As an insecticide, however, it is superior to 6| per cent of 

 solution of carbolic acid by contact method, but not equal to a 6^ 

 per cent solution of carbolic acid used as a fumigant. The vapor 

 from the commercial article, containing considerable oil not very 

 volatile, seems to be heavy, and does not fill the space as readily as 

 the vapors from an aqueous solution. 



Pyrethrum was tested similarly as a fumigant, and proved not 

 to be superior to cimicifuga, the insects recovering in every in- 

 stance. Employing the contact method and using the powdered 

 drug, the usual results were obtained that every one has experi- 

 euced who has used this well-known insect powder. 



I am indebted to Mr. G. N. Watson for his valuable assistance 

 in these determinations. 



