438 Expetiments and Researches 



In fact, neither alkalies, nor alkaline carbonates, precipitated 

 any other substance from the bittern of sea-water, except mag- 

 nesia. 



The deposit obtained at Portsmouth during the early period 

 of the concentration of the water, being analysed, I found it 

 to consist of selenite, mixed with a little muriate of soda, and 

 a portion of carbonate of lime. The presence of this last sub- 

 stance in sea -water, in a state of perfect solution, being, I be- 

 lieve, a new fact, I neglected no means of establishing it with 

 certainty, an object which was accomplished without diffi- 

 culty *. 



Carbonate of magnesia having been supposed by some che- 

 mists to exist in sea-water, I looked for it in the same deposit ; 

 but I could not detect the least portion of it by the most deli- 

 cate tests f. 



I next turned my attention to the alkaline salts of sea-water : 

 and here I was more fortunate ; as I succeeded in ascertaining 

 beyond a doubt, that sea-water contains ammonia, as it yielded 

 sal-ammoniac by evaporation and sublimation. This result 

 was easily obtained. Some of the bittern being evaporated 

 to dryness in a retort, and a low red heat applied, a white sub- 

 limate appeared in the neck of the retort, which proved to be 

 muriate of ammonia. The mode in which this substance was 

 identified was as follows : 



1. The sublimate was re-dissolved in water, re-evaporated 

 to dryness, and again sublimed by the heat of a spirit-lamp. 



2. This new sublimate being again dissolved, and solution 

 of magnesia and phosphoric acid added, a triple phosphate was 

 formed. 



3. On adding caustic potash to the solution, and bringing 

 the mouth of a phial containing muriatic acid close to the ves- 

 sel, abundant white fumes appeared. 



4. The sublimate gave precipitates both with muriate of 

 platina and nitrate of silver %. 



Sulphate of soda having been mentioned by many chemists, 

 as one of the constituents of sea-water, I endeavoured to as- 



♦ The deposit was treated with acetic acid, which occasioned an effer- 

 vescence. The clear liquor being then decanted off) and evaporated to dry- 

 ness, and alcohol added, acetate of lime was fouiTd in the filtered alcoholic 

 liquor. 



f Namely, solution of the mass in dilute muriatic acid ; precipitation of 

 the lime, and addition of phosphate of ammonia to the filtered liquor. 



X As it did not enter into my plan, on this occasion, to turn my atten- 

 tion to the estimation of proportions or precise quantities, I have not at- 

 tempted to estimate exactly the proportion which ammonia bears to the 

 other ingredients of sea-water; but as its presence can easily be shown in 

 100 grains of the bitter salts, its quantity cajinot be extremely minute. 



certain, 



^ 



