262 



EXPERIMENTAL FARMS 



4 GEORGE V., A. 1914 



these ' deterrents ' or soil disinfectants in Canada is as yet limited, but such as there 

 if* has not been very favourable from the economic standpoint. It will be understood, 

 therefore, that at the present time we are unable to recommend them and that further 

 experimental work is necessary to establish their usefulness and efficiency. The 

 analysis of a similar preparation (Vaporite) will be found in the report of this 

 Division for 1908. 



COAL-TAR DISINFECTANTS AND DETERRENTS. 



Two products of this nature forwarded by the Kingsdale Poultry and Supply 

 Co., Sussex, N.B., have been submitted to analysis. 



' Cow Spray/ Laboratory No. 11325. — This is probably a by-product of coal dis- 

 tillation below 250° C. It consists almost entirely of coal tar %drocarbons, one-third 

 of which distils over below 150° C. (light oils of the nature of kerosene) and a second 

 third between 150°C. and 210°C. The remaining third consists of heavy napthalene 

 oils, distilling between 210°C. and 240°C. There is present a small amount of tar 

 residue. We have no knowledge as to its practical usefulness as a protection to cattle, 

 against flies, but preparations of this character have been advocated and used for 

 this purpose. 



'Lice Spray,' Laboratory No. 11326. — This is an emulsion consisting essentially 

 of coal tar hydrocarbons and a resin soap. It probably contains cresols or analogous 

 bodies. Coal oil (kerosene) has long been used, and with success, for ridding the 

 poultry house of lice, and there seems little reason to doubt that a preparation of 

 this nature would serve the purpose equally well. It remains to be shown, however, 

 that it would be more efficacious or cheaper than the older and well-tried remedy. 



LEAD ARSENATE. 



Three brands of this insecticide have been analyzed, the samples being submitted 

 by the Horticultural Division which had them under trial in the Farm's orchards. 



Analysis of Arsenate of Lead. 



It is quite evident from the results obtained in the labratory that considerable 

 difference in lead arsenate content exists among the various brands of this insecticide 

 upon the market. As we pointed out in a previous report there are, no doubt, diffi- 

 culties of manufacture that militate against turning out continuously a product 

 absolutely constant as to water-content (which necessarily fixes the lead arsenate 

 content), but there seems no reason, if good methods are used, why greater uniformity 

 than is to be observed to-day could not be attained. Many firms are now putting t 



