Experiments oh Sea-lVaier. 203 



the great masses of sweet ice of the polar seas ? I would not 

 say that that ice is not of maritime origin on account of its 

 sweetness, as there is reason to believe that sweet ice might be 

 formed through seas where the salt is diminishing as they ap- 

 proach the poles, particularly where at a stationary low tem- 

 perature the less salt or nearly sweet water might freeze witli- 

 out agitation ; and, besides, water descending from the air might 

 contribute to its increase. But, besides fields floating from 

 the North, I should incline to refer to the frozen waters of ri- 

 vers and lakes, dissolved by thaw, a great quantity of those 

 pieces of ice which encumber the shores of less sweet seas. 

 The ice of theh" water cannot be deprived entirely of its salt, 

 and particularly when formed with agitation, as would be the 

 case at any degree above 18". Meanwhile those ices have been 

 Ibund every where sweet by the majority of voyagers, and so we 

 receive them, from the shores of Norway and Iceland. I would 

 finish here, but allow me to add that the specific gravity of the 

 sea-water of om* experiments is 1 '020. 



I am, with respect, sir, 



Your most obedient servant, 

 2, Foubert's Place, Regent-street, B. De SANCTIS, M.D. 



June 21, 1822. 

 To Professor Millingt07i. 



P.S. — After having written this letter, two other reflections 

 occurred to my mind, which seem not unworthy of being men- 

 tioned in addition to the former ones. 



1. Shoiild the process of the sea-water distillation ever be 

 rendered, by particular construction, more easy and not at all 

 troublesome to seamen, the distilled water might perhaps un- 

 dergo a further improvement under zceing ; it is an experi- 

 ment at least to be tried at large. The vegetable and animal 

 substances which seem not to be disposed to separate from the 

 crystals of the sea-water, might perhaps separate where they 

 are not surrounded by any salt drops. Besides, when tlie 

 sweet ice of the ship was nearly finished, a new provision might 

 perhajis be obtained from the iceing of the distilled water more 

 fit for resisting fusion than the salt ice. At any rate, the mu- 

 riate of lime could always be obtained again clean and equally 

 power fulfrom its solution in the distilled sea- water : which cir- 

 cumstance is rather of importance. 



2. Might not the electrical discharges through tlie cold air of 

 the polar regions favour the crystallization of the acjueousvapoius 

 of the atmosphere, as they favour the formation oi" the frost and 

 snow and hail in our ap|>aratuses ? Such discharges must be 

 very iieqiuiut in the polar regions, as the very rotation of the earth 

 unci of the surrounding air must necessarily develop electricity 



ifl 



