1816.) Prevost’s Theory of Radiant Heat. 995 
ingredients of sea-water ; and as his dissertation was published in 
Sehweigger’s Journal, September, 1814, the anticipation, it is 
remarked, is at least that of a year. Though the volume of the 
Transactions of the Royal Society of Edinburgh, in which my 
paper appeared, was published in June, 1815, yet the paper was 
read on the 20th of November, 1814; and the analysis itself was 
executed in August and September, so that, strictly speaking, there 
cannot be said to have been any anticipation. Besides, there is no 
novelty in the mere observation that muriate of lime, and sulphate 
of magnesia, or sulphate of soda, may exist together in a mineral 
water, for this has often been advanced, and has always been 
ascribed to the circumstance to which it is referred by Pfaff; the 
state of great dilution. The novelty of opinion consists in the 
inferring that these salts are the ingredients of a mineral water, 
from the obtaining by its analysis muriate of soda, or of magnesia, 
and sulphate of lime, and of course, regarding these latter not as 
original ingredients, but as products of the operation. Of this 
Pfaff seems to have had no idea, and could not indeed have had, - 
as the account which he gives of the composition of sea-water is 
incompatible with it. He states sulphate of lime as an ingredient, 
as well as muriate of lime, which he would not have done, had 
he had any conception of the above opinion. His statement of 
the composition of a mineral water, which you give in the same 
page, is equally incompatible with it. The ingredients: of that 
water, according to the view I have given, are carbonate of soda 
and muriate of lime, and not, as he states them, carbonate of soda, 
muriate of soda, and carbonate of lime. 
Se 
ArTicLE VII, 
Proceedings of Philosophical Societies. 
ROYAL SOCIETY. 
On Thursday the 25th of January a paper by Sir Humphry 
Davy was read, containing further experiments on the effect of 
wire sieves to prevent the combustion of gases from passing through 
them. A sieve formed of wire .!,th of an inch in diameter, and 
containing 10 wires in the inch, prevented the combustion from 
penetrating; but when agitated in an exploding mixture explosion 
took place. The explosion likewise took place when the wire 
became red-hot. When there were 14 wires in the inch agitation 
did not occasion an explosion. With 24 wires to the inch, the 
mixture did not explode even when the wire became red-hot. The 
author accounts for these singular phenomena in this manner. A 
red-hot wire of a considerable size is required to produce an ex- 
