J. V. Eyre, E. S. Salmon and L. K. Wormald 289 



to them and taking the golden yellow solution formed. The results of 

 analysing Solutions VIII and IX showed them to consist practically 

 entirely of ammonium trisulphide (NH4)2S3 in solution. 



Solution X. A current of sulphuretted hydrogen gas was passed 

 through a litre of a solution of ammonia in water (sp. gr. 0-980 at 15° C.) 

 until it was practically saturated. An aqueous ammonia solution of 

 the same strength was then added until by testing with copper sulphate 

 solution it was found that (NH4) and (S) were in the proportions 

 required to form (NH^jgS. An excess of flowers-of-sulphur was then 

 added and the liquid -^'as warmed by placing the flask containing it in 

 a water bath, the temperature of which was not allowed to rise above 

 80° C. When no more sulphur seemed to dissolve, the deep red liquid 

 which resulted was poured off from the undissolved sulphur and put in 

 a well stoppered bottle. This liquid formed the Stock Solution No. X. 

 When kept in a stoppered bottle, this solution remained clear but on 

 dilution with water it became cloudy in a few minutes owing to the 

 deposition of sulphur. 



Solid ion XI. During the preparation of Solution VIII, crystals of 

 (NH4)2Sg were formed and these were separated from the mother-liquor. 

 Solution XI was made from that mother-liquor by mixing 250 c.c. with 

 250 c.c. of an aqueous ammonia solution (sp. gr. = 0-926 at 11° C). The 

 specific gravity of Solution XI at 15° C. was 1-075. 



Lime sulphur. In the course of these experiments, the following 

 two solutions of lime sulphiu- were used. 



Solution XII. A mixture of 55 grms. of calcium oxide, llOgrms. 

 of flowers-of-sulphur, and 400 c.c. of distilled water was boiled under 

 a reflux condenser for 1| hours. This was left to stand for about 12 

 hours when the clear dark red liquid was decanted from the insoluble 

 residue into a well stoppered bottle. After standing for two weeks, 

 a few small crj'stals were observed to have separated. The clear liqmd 

 was separated from these and formed the stock solution for the spray- 

 fluids. The specific gravity of this stock solution was 1-221 at 10° C. 



Solution XIII. This was a commercial sample of lime sulphur. 



The results of the analysis of both the above solutions are given on 

 p. 306. 



In preparing the actual spray-fluids from the stock solutions, distilled 

 water was invariably used. The stock solution was dihited to such a 

 volume that the concentration was double that finally required in the 

 actual spray-fluid and this solution was mixed with an equal volume of 

 a 2 % solution of soft soap. For instance, where a wash containing 



