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



in excess, boiled briskl}' for half an hour and filtered ; filtrate 

 evaporated quickly to dryness, residue digested in boiling 

 ■water, and undissolved portion added to precipitate on filter ; 

 pi'ecipitate of carbonate of magnesia washed, dried and ig- 

 nited, gave 3*74 grs, of magnesia. 



To determine the quantity of carbonic acid in combination 

 with this, we have 20-G7 : 22 : : 3-74 : 3-99, this added to 374 

 grs. of magnesia, gives 7'73 grs. of carbonate of magnesia. 



3. From this it appears that the total quantity of carbonic 

 acid in combination with lime and magnesia is 4'86 + 3'99 

 = 8-85 grs. 



To verify this, the carbonic acid was determined directly 

 from the insoluble portion of 50 grs. of ash (A. 2). This 

 insoluble matter weighed 31*87 gi'S- oi' G3*74 per cent. Of 

 this, 14-27 gi's. decomposed by hydrochloric acid in flask 

 apparatus, gave 2*07 grs. of carbonic acid. Now 



14-27: 63-74 :: 2-07:9-24. 

 This quantity differs by 0-39 from S-85, the calculated quan- 

 tity. The excess is probably due to the escape of a little 

 hydrochloric acid during the boiling of the liquid in the flask 

 apparatus. The estimation of the lime and magnesia is more 

 to be depended upon than that of the carbonic acid. 



Summary. 



The phosphoric, carbonic and silicic acids exist both in the 

 soluble and insoluble portions of the ash. 



The total quantity of phosphoric acid has been already 

 estimated ajaproximately at 14-64 per cent. (C. II. 9). 



The quantity of carbonic acid in the soluble portion is 2-16 

 (B. I. 2), and in the insoluble 8*85 (C. III. 3), making toge- 

 ther 11-01 per cent. 



The quantity of silica in the soluble part is 2*44 (B. II. 1), 

 and in the insoluble part 15-44 (C. I.), making together 17'88 

 per cent. 



The total quantity of lime is 14-15 per cent., viz. 7*97 

 in the phosphate, and 6-18 in the carbonate (C. II. 6, and 

 C. III. 1). 



The magnesia amounts to 5-34 per cent., 1-60 being in the 

 state of phosphate (C. II. 7) and 3*74 in that of carbonate. 



The total quantity of alkaline bases (potasli and soda) is 

 20-11 per cent. (B. II. 3). From this we must deduct the 

 quantity of oxygen corresponding to 2*26 of chlorine (B. I. 4), 

 viz. 0-51, because portions of the potassium and sodium are 

 in the state of chlorides. 



Finally, then, we have for the constituents of the hop-ash, — 



