BREAD OR PASTE BEETLE. 109 



seed, I am not aware of it as a borne trouble. If it should appear 

 here, it would be worth while to try what kinds of steeps or dressings 

 would check progress of the mischief without lessening vitality or 

 power of germination of the seed. Experiments on this point made 

 by some of our large firms who have expert advisers might be very 

 useful to themselves for communication to their consignees. 



Alum has long been known as destructive to this kind of maggot, 

 but I have no notes of its coincident effect horticulturally considered, 

 and various other applications which might (harmlessly to the seed) 

 be of service are probably too well known to need mention. 



But this special seed infestation, in which the treatment would lie 

 in skilled hands, might prove to be one in which the use of fumigation 

 with bisulphide of carbon would do everything that is needed. We 

 know of it as a remedial measure constantly used in Canada and the 

 United States, and I give one of the most trustworthy recipes with 

 which I am acquainted for method of its application to infested flour, 

 but which would only need a little adaptation for other infested 

 materials : — 



" A small quantity of the chemical is sufficient for the disinfection 

 of a barrel of flour, as the insects for the most part live only in the 

 flour at the top, being unable to withstand the pressure of a large 

 weight of material. From a half to a whole teacupful (about two to 

 five ounces) of the bisulphide will prove sufficient for the purpose in 

 an ordinary case, provided the cover be replaced as tightly as possible. 

 In more severe cases of infestation it may be necessary to repeat the 

 application. The bisulphide is poured into shallow pans, or plates, 

 placed upon the top of the infested mass, and the receptacle covered 

 as closely as possible, and left for a day or more. This chemical is 

 extremely volatile and, being heavier than air, descends as a gas, 

 killing such insects as the material may contain. When an entire 

 room or building is overrun with insects, the bisulphide is evaporated 

 at the rate of a pound to every thousand feet of cubic space. The 

 vapour of the chemical is deadly to all animal life, but there is no 

 danger in inhaling a small quantity ; and although it has a powerful 

 and disagreeable odour, this soon passes away without any after effects, 

 and without harming for food such material as it may be used upon. 

 The vapour is also inflammable, but if no fire, as, for example, a 

 lighted cigar, be brought into the immediate vicinity until the fumes 

 have entirely disappeared, no trouble will be experienced." 



The above stands on the high authority of Dr. Howard, Entomo- 

 logist of the U.S.A. Department of Agriculture, and Mr. C. L. Marlatt, 

 First Assistant on the Entomological Staff; and as the advice to use 

 this application is still regularly continued both in the United States 

 and Canada without reports of accidents, and also, as far as I am 



