150 



Dr. J. Monokman. The Specific 



To avoid the addition of any objectionable body, no attempt was 

 made to precipitate the sulphur from the sulphur dioxide, hence half 

 the sulphur present was lost. 



Thus it will be seen at once that a considerable quantity of the 

 salt was required to produce a very small quantity of pure sulphur. 

 14 lbs. of the hyposulphite were dissolved, filtered, and decomposed 

 by acid, then washed until free from salts and acids, dried, and 

 distilled several times. When the residue appeared to be perfectly 

 free from foreign matter it was repeatedly distilled in vacuo, the 

 middle portion being removed. 



In this method the only solvent was water, and the other bodies 

 produced could be tested for by delicate chemical reactions. I believe 

 that the three methods described fulfil the requirements mentioned 

 in an earlier portion of this paper, giving as pure sulphur as can be 

 prepared, but at the same time, the bodies that may have escaped 

 removal will differ in each specimen. 



