56 Mr. Watts on the Analysis of Hop- Ash. 



Chloride of potassium 30-68 p. c. = 19-41 p. c. of potash, 

 sodium 1*32 ... = 0-70 ••• of soda. 

 32-00 20-11 



C. Matter insoluble in water. 



1. Siliceous sandy matter. — Insoluble matter from 100 grs. 

 of ash (A. 1) boiled in hydrochloric acid: liquid evaporated 

 to dryness to render silica perfectly insoluble ; residue di- 

 gested in dilute hydi-ochloric acid ; undissolved matter, con- 

 sisting of silica and charcoal, collected on weighed lilter, 

 washed and dried at 300°. 



Silica and charcoal weighed . 18-26 grs. 

 Silica (after ignition) . . . 15-44 ... 

 therefore Charcoal 2-82 ... 



II. Earthy Phosphates. — 1. Filtered solution (C. I.) treated 

 with excess of ammonia yielded a precipitate which being 

 washed, dried and ignited, gave of earthy phosphates 27*26 

 grs. 



2. Phosphates, after ignition, dissolved in hot hydrochloric 

 acid and reprecipitated by ammonia ; precipitate digested in 

 warm acetic acid to dissolve phosphates of lime and magnesia ; 

 the insoluble portion consisting of phosphates of iron and alu- 

 mina weighed 8*25 grs. 



3. Phosphates of iron and alumina redissolved in hot hj^- 

 drochloric acid ; solution boiled with excess of caustic potash, 

 undissolved portion collected on filter, washed, dried and 

 ignited, gave 



Weight of phosphate of iron . =4-57 grs. 

 Therefore phosphate of alumina = 3*68 ... 



¥25 ... 



4. Alkaline solution (C. II. 3) boiled with sal-ammoniac, 

 gave a precipitate of phosphate of alumina, which weighed 

 only 1-8 gr. instead of 3-68; but the liquid filtered from this 

 precipitate gave, \:hen treated by Berthier's process, a quan- 

 tity of phosphoric acid weighing 1-91 gr., which, added to 

 1-80 gr., gives 3-71 grs. for the quantity of phosphate of 

 alumina, differing by only 0-03 gr. from 3*68 grs. We may 

 infer from this that the quantity of phosphoric acid in com- 

 bination with alumina is about 2-5 per cent. 



5. To determine the quantity of phosphoric acid in com- 

 bination with oxide of iron, the 4-57 grs. of phosphate of iron 

 (C. II. 3) were redissolved in hot hydrochloric acid, and the 

 solution treated with ammonia and sulphuret of ammonium : 



