1922] 



YOUNG — THE TOXIC PROPERTY OF SULPHUR 



417 



Shaffer and Hartman method ('21) was 1.4. Sulphides were 

 found to be approximately 0.1 per cent. Precipitated sul- 

 phur as determined by the carbon bisulphide method gave 

 a percentage of 2.8. We have present then in the changed lime 

 sulphur, precipitated sulphur, calcium thiosulphate, calcium sul- 

 phite, and calcium sulphate. 



The toxicity of these individual compounds was next deter- 

 mined. Fifty cc. of 1 : 6 lime sulphur solution were set aside in a 

 large open vessel. After 36 hours the reaction had changed to Ph 



6.4. The solution was then removed and the vessel washed with 

 too. 



I 



b ea 



^ 







dC 



PnZ 



nannite-h^NaOh 

 Buffered Mixture 





3 



* 5 $ 7 6 



Fig. 4. Germination of spores of Macrosporium sarcinacforme in hanging- 

 drop cultures: toxic action of flowers of sulphur ■ ; of hydrophobic col- 

 loidal sulphur . ; of hydrophilic colloidal sulphur ; check, 



without sulphur . 



sufficient distilled water to make the total quantity up to the 

 original 50 cc. This mixture was then centrifuged until the 

 supernatant liquid was clear. A test was then made for calcium 

 thiosulphate in the supernatant liquid. The percentage was 1.4. 

 The part thrown out of the solution by the centrifuge was again 

 washed in cold water and again centrifuged. The washing re- 

 moved any soluble compound that might have been present. This 

 washed substance was then suspended in 50 cc. of distilled water. 

 The compounds contained in this suspension were the insoluble 



