24 



CIRCULAR NO. Ill, BUREAU OF PLANT INDUSTRY. 



presence of sulphur being indicated by a black precipitate of lead 

 sulphid which forms in the test tube. 



To avoid any mistake in determining whether or not grain has been 

 bleached it is advisable before making the test to make several 

 experiments with both bleached and unbleached grain and also 



HEAVY NECK 

 INSIDE DIAMETER 

 A PR OX I MAT ELY 1 in. 



GROUND GLASS 

 CONNECTION 



Fut. 1. -Improved apparatus for detecting sulphured grain, showing its dimensions and the manner of 



adjustment. 



with mixtures of the two. For example, samples containing 2 per 

 cent, 5 per cent, 10 per cent, and 50 per cent of bleached grain should 

 be tested, in order to become familiar with the appearance of the 

 precipitate when there is only a small quantity of sulphur present. 



[Cir. Ill] 



