414 



[Vol. 9 



ARDEN 





such as is found in the hydrophilic colloidal sulphur. The in- 

 fluence of the hydrogen-ion concentration was very striking, es- 

 pecially with this latter form of sulphur. Upon examination 

 of the culture tubes containing the hydrophilic colloidal sulphur 

 it was found that settling out was rapidly increased as the P H 

 increased beyond P H 5.4. 



riannik-t%FQf[WH- 

 Bofkrcd H/x,ure 



Flit 



J 



4 



5 



6 



7 



6 



Tig. 1. Germination of spores of Botrytis 



toxic action of flowers of sulphur 



-; of hydrophilic colloidal sulphur 



cinerea in hanging-drop cultures: 

 ; of hydrophobic colloidal sulphur 

 ; check, withe ut sulphur 



EXPERIMENT 4. 



UK 



The compounds formed in lime sulphur mixtures hs,ve been 

 fairly well determined by Haywood, Van Slyke, and others. The 

 reactions that take place when sulphur and calcium oxide are 

 boiled together are about as follows: 



3Ca(OH) 2 + 12S = CaS 2 3 + 2CaS 5 + 3H 2 

 or3Cu(OH) 2 + 8S-CaS 2 3 + CaS 3 + 3H 2 



These reactions are influenced, of course, by the initial ratio of 

 the ingredients. Varying 



amounts of CaS 3 , CaS 4 . CaS 5 , CaS 2 



and CaS0 3 are formed depending upon th 



When lime 



sulphur is prepared according to the Van Slyke method that 



