58 



Williamson (M. J.), A Description of the Cyanide Process for the 

 Extermination of Bugs.^ — Jl. R. Amny Med. Cotys, London, xxiii, 

 no. 6, December 1914. 



Experience with troops in South Africa showed that scrubbing 

 with cresol sohition, anointing witli paraffin and fumigating with 

 potassium permanganate are only partially successful for the destruction 

 of bugs, fumigation with potassium cyanide being the only satisfactory 

 method. For this purpose the quantities to be used for every 

 100 cubic feet of space are : potassium cyanide, 1 oz.; sulphuric acid, 

 1 oz. ; and water 2 oz. The spaces to be fumigated must be air-tight. 

 As generating vessels, ordinary paraffin tins should be placed in the 

 centre of each room ; the cyanide, of the requisite amount for each 

 charge, should be placed in stout paper or linen bags and water 

 measured out into the tins. At the last moment, the exit door of the 

 room must be made air-tight and finally the acid must be added to 

 the water and the cyanide added while the mixture is still hot and the 

 room sealed up for at least 4 hours. 



McClain (J. H.). Eradication of the cattle tick necessary for profitable 

 dairying. — U.S.Dept. Agric, Washington, D.C., Farmers' Bull, 

 no. 639, 19th December 1914, 4 pp., 2 figs. 



Even in so-called immune cattle, ticks irritate the skin and draw 

 blood to the detriment of the milk or flesh. The need of some definite 

 knowledge on this subject led the Department of Agriculture to 

 conduct some experiments on the effect of ticks on milk production 

 and body weights of dairy cattle. The main results obtained were 

 as follows : (1) Cows carrying ticks did not hold up so well in milk 

 as those kept free from ticks and did not increase their flow of milk 

 when the feed was increased, as did the tick-free animals. (2) At 

 the close of the experiments those lightly infested with ticks were 

 producing 18" 6 per cent, less milk than those free, practically 1 J pints 

 less per cow per diem. (3) The heavily infested cows were producing 

 42*4 per cent, less milk than the free animals, or nearly one-half U.S. 

 gallon less per head per diem. (4) During the experimental period 

 of one of the tests, which included 20 cows, the heavily infested animals 

 lost an average of 93 lb. in weight, while the tick-free animals gained 

 an average of 44"2 lb., although both lots were fed alike. (5) Cows 

 which had previously been infested with ticks and were supposed to 

 be immune, suffered from tick fever and one cow died. Spraying 

 caused a temporary falhng off of 61 per cent, in milk, but in from 

 three to five days the bad effects of the spraying disappeared. Like- 

 wise, the shock of dipping caused the animals to lose an average of 

 10' 6 per cent, in milk for two days, but after several dippings they 

 became less sensitive and only lost 1 per cent, after the last few 

 dippings. These losses are very small compared with those due 

 to tick infestation and it is far cheaper to take measures to destroy 

 the ticks. 



