PREPARING THE LIME-SULPHUR WASH. 



167 



close planting necessary to secure the i-esult de- 

 sired, the culture of such a garden must of ne- 

 cessity be done by hand. If the grape vines 

 are trained on the Kniffen high renewal system 

 they will serve both as a screen for the rest of 



the garden, and as a source of fruit supply. A 

 good wire fence should, however, be constructed 

 on the line between adjoining properties, and 

 the grape border planted not farther than two 

 feet from the boundary fence. 



ON A NEWLY-PROPOSED METHOD OF PREPARING THE 



LIME-SULPHUR WASH 



BY FRANK T. SHUTT, M.A , F.I.G., F.R.S.C, CHEMIST, DOMINION EXPERIMENTAL FARM. 



IN the report of the division of chemistry 

 in the experimental farms for 1902, the 

 results of a series of experiments in the pre- 

 paration by boiling of this valuable spray are 

 given. Since the appearance of that report 

 a method has been proposed by the New 

 York Geneva Experiment Station, which 

 obviates the necessity of boiling — the chief 

 drawback to the more common use of this 

 valuable remedy. The modification consists 

 in the addition, at a certain stage in the pre- 

 paration, of strong lye, such as Babbitt's or 

 Gillett's. The proportions and preparation 

 as given in Bulletin No. 228 of the above 

 named experiment station are as follows : 



Lime, unslaked, 40 lbs. 



Sulphur, ground, 20 lbs. 



Lye, concentrated, 5 to 10 lbs. 



Water, 60 gallons. 



" In the preparation of the mixture the 

 lime was slaked, preferably with hot water, 

 and while it is slaking vigorously, the sul- 

 phur, which had been made into a thin 

 paste, was added and thoroughly mixed with 

 the slaking lime. The caustic soda is then 

 added, with water as needed, and the whole 

 stirred thoroughly. As soon as the chemi- 

 cal action has ceased the required amount of 

 water, preferably hot water, is added, and 

 the mixture is re^dy for use." 



Tt will be noticed that in this process there 

 is no boiling and no salt, an ingredient in 



the old formula which apparently had no di- 

 rect value as an insecticide, but was useful 

 in raising the boiling point of the mixture, 

 thus ensuring a more complete union of the 

 sulphur and lime. 



At the request of the entomologist (Dr. 

 Fletcher) we made several trial prepara- 

 tions in the laboratory and found that the 

 proposed method is quite workable and sim- 

 ple and yields a product in which there 's 

 very little uncombined sulphur. This latter 

 is an essential point, as undoubtedly it is the 

 sulphur compounds that give this wash its 

 great value for destroying the scale. I^ is 

 necessary to this end that the sulphur be 

 added (in a thin paste) while the lime is still 

 actively slaking — for which purpose care 

 should be taken to use only a sufficiency of 

 water — and the mass stirred vigorously. As 

 soo^i as the sulphur paste is poured on to the 

 slaked lime add the solution of lye, with 

 such further quantities of water as may be 

 necessary, stirring and mixing, until all bub- 

 bling ceases. There is now an orange-yel- 

 low, pasty, homogeneous mass which can be 

 diluted to the requisite volume either at 

 once or at any subsequent time, if kept out 

 of contact with the air. 



As far as one can judge from what might 

 be called the chemical or physical point of 

 view, this wash should prove equally eflFec- 

 tive with that prepared by boiling. 



