1823.] on the Saline Contents of Sea-Water. 263 



on careful examination, it did not appear to contain the smallest 

 atom of corrosive sublimate. • , 



I next dissolved five or six pounds of bay-salt m water and 

 collected in a filter the insoluble earthy sediment, which 

 •Rouelle stated that the quicksilver was usually found. I ins 

 Sent bring carefully dned, and heated to redness in a coated 

 retort ^ white" sublimate arose, and condensed on the neck ol 

 the retort : but this sublimate proved to be muriate of ammonia, 

 and did not contain the smallest portion of corrosive ^sublimate, 

 o other mercurial salt. This sal-ammoniac, though evidently 

 formed during the distillation from the vegetable and animal 

 matter contained in the sediment, suggested to me the idea of 

 lookino- for ammonia amongst the contents of sea -water. 



I now submitted some Sel de Gabelle, winch I had procured 

 from Calais for the purpose, to similar experiments, and the 

 sea ment, also, was carefully examined The result was essen- 

 tialh) the same as with the bay-salt. After adding nitric acid to 

 the salt the heat was gradually pushed to redness ; and when 

 aU the Amis tore was evaporated; I white sublimate appeared, as 

 i* the former case, which, in this instance proved to consist 

 almost entirely of nitrate of soda ; but always without the 

 least particle of mercurial salt, and without any muriate of 



a TthTrefore think myself justified in concluding that the mer- 

 curv which other chemists have detected m sea-salt or its pro- 

 S, must have been introduced there from some local or acci- 

 dental circumstances. . ^ ,. 



In experiments upon sea-salt, or in general upon the sa me 

 contents of the sea, it is obvious that, in order to exclude 

 sourcs of error, it is necessary to operate upon pure sea- 

 water and not upon salts obtained from it by the usual pro- 

 cesses in the laro-J way, these being always more or less conta- 

 nnnatea bY tle r °i ay $. m which tSe evaporation is carried on, 

 "; the metallic boifeJs, or other adventitious causes. I ***■ 

 fore now turned my attention to the sea-water itself, and in par- 

 ticu aTthe perfectly pure and transparent specimen of coaee* 

 trated brine from the Channel, which I have above mentioned. 

 Mr Barry procured this water near Bembndge "oaring light 

 about tworailes north-east of the eastern extremity of the Isle of 

 Wi*h an™ the evaporation which it had undergone at Por t- 

 umuth; had only separated from it a quantity of calcareous 

 matter, principally selenite.t 



dually conducted than ^^ ■gj««g- ft . & had been aUoW ed to stand 



hudly »y Out I couM no: MM i»» U» '«»« !'«"* »' ,h " ■"* 



