WATER OF THE SEA. 591 



curing provisions, it ought to undergo a particular refining Observations 

 . ..... ^ . , . „ \. and facts re- 



operation to nd it of Its foreign admixtures. For want of specting the 

 such a process, some sorts of sea salt, though fair to the eye, component 



. . ,,•.,,•"• parts contained 



do not possess an intire and undivided antiseptic power, but so in sea water, 



far as the muriate of soda in the mass is alloved by the mid- an<5<^he useful 

 „ , . . , , • " . . , applications of 



die salts ot magnesian and calcanous composition, those that fluid- 

 parcels of common salt so vitiated become unfit for opposing 

 completely the process of putrefaction. And so far they 

 make a departure from the antiseptic power of pure muriate 

 of soda, the manner of whose action, I endeavoured to in- 

 vestigate in a Memoir addressed to professor Woodhouse and 

 published in the second volume of the New York Medical 

 Repository. 



By reason of these foreign and adventitious matters, it 

 happened in Sir John Pringle's' experiments, that the com- 

 mon salt employed by him, instead of preventing the cor- 

 ruption of meat, when added in small quantity rather promo- 

 ted its decay. (Paper III. Exp. S-i.) His trials he ob- 

 serves were made with the white or boiled salt kept there (in 

 London I suppose he means) for domestic uses. (Appendix 

 to Observations on Diseases of the Army, &c. p. S^S, 

 Note.). This kind of salt is known to abound witli the earthy 

 salts with which ocean water is charged. 



Dr. Percival's experiments on sea salt have a tendency to 

 shew that the septic quality ascribed by the learned Baronet to 

 small quantites of common salt is owing to the mixture of 

 bitter salt with it. ' A quantity of this, he observes, adheres 

 to all the common salt used for culinary and dietetic purposes^ 

 and as far as its influence goes, it counteracts the wholesome 

 and preservative powers of the clean and unmixed muriate of 

 soda (1 Essays Jvledical, &c. p. 344,) and that this septic 

 quality of the sea salt depended upon the presence of some 

 heterogeneous substance was the opinion of Pringle himself, 

 (Ibid. p. 347.) 



Such then being the composition of ocean water, it is easy 

 to explain wherefore it is not fit by itself, for washing gar- 

 ments and making them clean. It has a deficiency of o/Aa- 

 line salt in it; and alkaline salts are well known to be the 

 most excellent and complete detergents. And it is quite a§ 



easy 



