of the State of New York. 267 



plainest manner, the comparative value of the specimens which I 

 examined. The following is the process which I adopted. 



A. Five hundred grains of the specimen under examination were 

 dissolved in^six or eight ounces of water, heated to about 200° Fahr. 

 and the solution filtered. The matter on the filter was again washed 

 with a small quantity of water, and after being perfectly dried, was 

 weighed, and the amount set down as insoluble residuum. 



B. The insoluble matter was treated with dilute nitric acid, and 

 then tested with various reagents. It generally consisted of carbon- 

 ate of lime, oxide of iron and silex, although the proportions were 

 very various. These I did not think it necessary, in each case to 

 determine. 



C. The weight of the filtered solution A, was now determined, 

 and to a known portion of it, acetic acid was added until the alkali 

 was completely neutralized. 



D. To this neutral solution, solution of acetate of baryta was ad- 

 ded as long as it caused any precipitation, and the whole then filtered ; 

 the resulting sulphate of baryta, being dried and weighed, gave by es- 

 timation, the amount of sulphuric acid contained in the whole solu- 

 tion (A.) ' Supposing this acid to be combined with potash, the 

 amount of sulphate of potash, in the sample under examination, was 

 easily settled. No account was taken of the small quantity of sul- 

 phate of lime, which might be contained in the solution. 



E. To the filtered solution D, nitrate of silver was now added, as 

 long as any thing was thrown down by it. The resulting precipi- 

 tate was dried and weighed. This was chloride of silver, and from 

 its weight, by estimation, the whole amount of chlorine was deter- 

 mined. Supposing this to have been originally combined with po- 

 tassium, the amount of chloride of potassium was deduced. 



Although from several experiments, I was satisfied that soda was 

 also contained in most of the specimens which I examined, the cu- 

 rious play of affinities between the salts of soda and of potash, ren- 

 dered it difficult to determine the exact state of combination in which 

 it existed. Indeed, the process required for their separation, espe- 

 cially when the soda is in small proportion to the potash, is so deli- 

 cate as to preclude its employment in ordinary inspection. It may, 

 however, be of use to the inspector, to be aware of the different ef- 

 fects produced upon the carbonates of potash and soda by exposure 

 to the air ; the former as it is well known to chemists, soon becomes 

 moist and assumes the liquid form, while the latter is not thus afFec- 



