34 ESSAY III. 



of the whole operation had gained, and by which they ex- 

 ceeded the loss of the matter in the retort. 



SECTION X. 



This began at once to throw light on the controverted 

 point. For where are the 5 drms. 10 grs. which the glass 

 of the retort had lost, but in the products obtained out of 

 the retort ? In order to examine these, the fluid in the 

 receiver was diluted with 4 oz. of distilled water, and poured 

 on a filter, that the clear liquor might be separated from the 

 earthy crust which floated in it ; fresh water was poured on 

 the filter as long as the earth retained any sour taste. The 

 empty receiver was found, upon weighing, to have lost no 

 sensible part of its original weight. The earth remaining on 

 the filter weighed, after it had been dried, 57 grs. 



SECTION XI. 



The clear liquor was then diluted with more distilled 

 water, and afterwards precipitated with spirit of sal 

 ammoniac, prepared with fixed alkali and water, which was 

 added till the smell of volatile alkali indicated the point of 

 saturation. Before any precipitate began to fall, there was 

 a brisk effervescence, that continued for some time. The 

 precipitation itself took place without effervescence ; there 

 was present, therefore, a quantity of unsaturated acid. The 

 semitransparent gelatinous precipitate not having quite 

 reached the bottom the next day, the whole was poured 

 upon a filter, and when the liquor had passed through, 

 fresh water poured upon the precipitate as long as it 

 retained any saline taste. After drying, it weighed exactly 

 2 drms. 



