1823.] on the Saline Contents of Sea-Water. 265 



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 vessel, 

 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 ascer- 

 tain, whether or not it existed in it. But all attempts to detect 

 this salt in the bittern by crystallization were fruitless, though 

 great pains were taken for that purpose ; and I feel the more 

 confident that there is no sulphate of soda in sea-water, as the 

 presence of this salt in any but the most minute quantities 

 would be quite incompatible with our knowledge of chemical 

 affinities. For since there are co-existing in sea-water muriate 

 of soda and .sulphate of magnesia, it is evident that sulphate of 

 soda would decompose muriate of magnesia, which salt is known 

 to be in sea-water. And again we know, that sea-water con- 

 tains sulphate of lime and muriate of soda ; therefore it cannot 

 contain sulphate of soda ; for in that case we should have 

 muriate of lime, which I have shown to be contrary to fact. 



The last circumstance which I shall at present notice relates 

 to the state in which potash exists in sea-water.f Potash is 

 found, by its appropriate re-agents, principally in the bittern, 

 but it is found also among thei salts which are separated from it, 

 especially in the latter period of crystallization. By further and 

 repeated evaporation of the bittern, and successive separation of 

 the mother water remaining after the removal of the crystals 

 formed, various distinct crystals were obtained possessing their 

 characteristic form ; namely, prismatic sulphate of magnesia, 

 cubic and star-shaped muriate of soda, and rhombic crystals, 

 quite different from either of the other salts. These crystals, 

 which were evidently portions of an oblique rhombic prism, 

 being carefully separated and washed with water and alcohol, 



• As it did not enter into my plan, on this occasion, to turn my attention to the esti- 

 mation of proportions or precise quantities, I have not attempted to estimate exactly the 

 proportion which ammonia bears to the other ingredients of sea-water ; hut as its pre- 

 sence can easily be shown in 100 grains of the bitter salts, its quantity cannot be 

 extremely minute. 



■f- It will be recollected that the presence of potasli in sea-water, though announced 

 by myself in the paper on sea-water to which I have before alluded, was Dr. AVollaston's 

 discovery. I have likewise to mention, that the abo\e experiments respecting the state 

 in which it exists, were either made by him or at his suggestion. 



