REPORT OF THE CHEMIST. 



185 



SESSIONAL PAPER No. 16 



CHEMISTRY OF INSECTICIDES AXD FUNGICIDES. 



WHALE-Oir. SOAP. 



The efficiency of a wash or spray made from whale oil soap, as a means of 

 destroying many soft-bodied insects, has long been known; during the past few years, 

 however, this insecticide has received special and increasing attention from fruit 

 growers. It is now advocated and largely used for San Jose scale, Oyster-shell Bark- 

 louse, plant lice, (tc, and information regarding the preparation and application of 

 this remedy will be found in the present report of the Entomologist. 



The term whale-oil in this connection appears to be synonymous with fish-oil; 

 indeed, according to some authorities, practically all the brands of ' whale-oil ' soap 

 upon the market are made from fish oil. The character of the oil used is said to affect 

 the insecticidal power of the soap; and some suppose it is the whale oil that imparts 

 the peculiar virtue to this wash. 



It is considered essential for the effrcient action of this soap that it 

 should be made with potash and not soda. Potash makes ' soft ' soaps, which are 

 viscous or semi-fluid ; soda gives ' hard ' and solid soaps. It i> probable that potash 

 soaps make the better and more adhesive wash when a hard water has to be used, but 

 whatever may be the cause for the preferment, entomologists are of one mind in 

 considering that potash soaps only should be used. 



At the request of the Entomologist (Dr. Fletcher), we have examined several 

 brands, the samples Xos. 1 To 6. inclusive, being received through the kindness of Mr. 

 Geo. E. Fisher, Freeman, Ont. In the following table the percentages of water and 

 potash are given. From these data the comparative value of the soaps may be 

 deducted ; those containing the smaller percentage of water and larger percentage of 

 potash obviously being the better: — 



Analyses of Soft Soaps. 



Date 

 Received, 



inoo. 



Water. 

 Per cent. 



Potash. 

 Per cent. 



Mav 18th . 

 .- 18th . 

 „ 18th. 

 .. 18th. 

 .. ISth. 

 M 18th . 

 J. J. Ward,' Consecon April 17th 



Owens whale-oi! .';oap 



Home' made soft soap 



Toronto Peerless soft oil soap 



Toronto whale-oii soap 



Hamilton vegetable oil soap. 

 London soap 



31 

 •17 

 •78 

 •6.5 

 •47 

 •62 

 •054 



In speaking of the composition of soft soaps, Allen, in his ' Commercial Organic 

 Analysis,' Vol. IL, Pt. I., p. 300, says: 'But few complete analyses of soft soaps have 

 been published, but the proportion of water in samples of good quality is usually 

 between 35 and 45 per cent, whilst the anhydrovis oxide (potash) varies from 8 -8 to 11 "2 

 per cent.' Leaving out of consideration No. 7, which is a soda soap, it will be seen 

 that the majority of the samples examined are below the standard here given. 



' Can the whale-oil soap used in spraying for San Jose scale benefit the tree in 

 any way other than as an insecticide ? ' This is a question frequently asked of us. 

 Many orchardists affirm that there is a m^arked effect upon the vigour of the tree, as 

 shown by the colour of the foliage and the improved appearance of the fruit, that 

 can scarcelj' be attributed to the insecticidal properties of the soap. We offer the 

 following as an answer to the foregoing question and as a probable explanation of 

 the statement just cited: — * 



Whale-oil soap of good quality will contain from 9 to 12 i>er cent of potash. This 

 element, as is well known, is an important and valuable constituent of plant food. 



