REPORT OF COMMITTEE ON PUBLICATION 173 



of the water liberated but without volatilizing any of the sulphur, and form 

 a final product containing about 37 per cent sulphur."i 



So far as indicated by anaFyses, the resulting product is practically the 

 same in either case, and the diluted spray would be essentially the same as 

 the home-made wash proposed by Haywood in 1907.2 The manufacturers 

 claim from 54 to 62 per cent of total su'phur for their products but the 

 samples thus far examined in the Insecticide Laboratory have had consider- 

 ably less than this amount, usually running about 50 per cent. The highest 

 official published analysis seen elsewhere reports 58 per cent, of total sulphur. 



COMPATIBILITY CF THE SULPHUR FUNGICIDES. 



Sulphur: So far as chemical action is concerned, sulphur may be mixed 

 with practically any of the sprays which are in common use. Strong alkalies, 

 however, might dissolve enough of the sulphur to cause foliage injury. The 

 aversion of sulphur to water, however, prevents its mixing readily with it or 

 with the sprays, the latter being a physical incompatibility. 



Wettable Sulphur Sulphur Pastes: The addition of oleic acid, glue, or 

 diatomaceous earth as deflocculating agents does not change the compati- 

 bilities of sulphur. The constituents of iron sulphide are not affected by the 

 ordinary spray materials. Therefore the preparations described under this 

 heading are both physical and chemically compatible with all of the sprays 

 in general use. 



Lime-sulphur: Lime-sulphur solution is chemically incompatible with 

 Bordeaux mixture. It is thought that the fungicidal value of Bordeaux is not 

 destroyed by mixture with lime-sulphur solution, but a part of the soluble 

 sulphur of the latter is looked up as an insoluble copper sulphide which is 

 valueless for the destruction of mildews. 



Lime-sulphur solution is chemically incompatible with all arsenlcals (ex- 

 cepting basic or neutral lead arsenate), chemically and physically incom- 

 patible with soaps and emulsions, and chemically incompatible with acids 

 and alkalies. 



It is compatible with tobacco preparations and with basic or neutral lead 

 arsenate. 



Alkali Sulphides and Polysulphides. Chemically incompatible with Bor- 

 deaux mixture. 



Chemically incompatible with all arsenicals (excepting basic or neutral 

 lead arsenate), and with acids. 



Compatible with soaps, emulsions, alkalies, tobacco preparations, and 

 basic or neutral lead arsenate. 



Summarizing the discussion on compatibility, the following points were 

 shown: (1) Sulphur is unsuited for use in any of the sprays on account of 

 its physical incompatibility with aqueous solutions. (2) Paste sulphurs and 

 wettable sulphurs offer a distinct advantage over the other sulphur fungicides 

 owing to their compatibility with practically all of the common sprays, their 

 compatibility with Bordeaux mixture probably being the most important 

 desirable quality of interest to viticulturists. They are the only type of 

 sulphur fungicide permissible with Bordeaux mixture. (3) If used in the 



i U. S. Patent reissue 13,796, Chemical Abstracts, 8, 3480. 

 2Loc. cit. 



