> BICHARDS AND PARKER. — BARIC SULPHATE. 



73 



of the occlusion. Many of the experiments above were made with 

 this idea in view. 



The two experiments numbered 18 and 19 may be taken as types of 

 the usual method of working. The volume of the sulphuric acid was 

 about fifty, and that of the baric chloride about twenty cubic centi- 

 meters ; the latter solution was slightly in excess, and was poured 

 gradually into the former. 



Series II. 



In order to determine whether an excess of baric chloride increases 

 the occlusion, a similar series was made, using twice the amount of 

 baric chloride necessary for the precipitation. 



Series III. 



Since this average is not greater than the last (0.0052), no occlu- 

 sion could have taken place after the precipitatation was complete, and 

 the only effect of the excess of baric chloride was to diminish the solu- 

 bility of the precipitate (see page 71). 



In the next series the sulphuric acid was poured into the baric 

 chloride, instead of vice versa. 



