The uncertainty that has till now prevailed concerning the nature and composition of the ores of zinc called Calamine, has induced our author to enter upon the investigation now before us. In the first part of the paper, we find the analysis of four kinds of calamines; the first from Bleyberg in Carinthia, the second from the Mendip hills in Somersetshire, the third from Derbyshire, and the fourth an electrical calamine from Regbania in Hungary. Referring to the paper for the detail of the four processes there circumstantially de- scribed, we must content ourselves with reciting here the results de- duced from each of them.
1000 parts of the Bleyberg ore were found to consist of 714 calx of zinc, 135 carbonic acid, and 151 water. Some carbonate of lime and lead were likewise found in it; but these appeared to be mere accidental admixtures, and in too small quantities to deserve notice.
1000 parts of the Mendip ore consisted of 648 parts of cab: of zinc, and 352 of carbonic acid, and yielded no water.
In the Derbyshire ore were found 652 of calx of zinc, and 348 of carbonic acid.
And in the Hungarian ore, 683 of calx of zinc, 250 of quartz, 44 water : and here there moreover appeared a loss of 23, owing, no doubt, to some defect in the manipulation. The water was by no means considered as an essential part of this ore; and hence the pro- portions of: the two other ingredients were as 739 to 261.
In a second part of the paper, the author communicates some ob- servations to which he was led by the uncertainty that still prevails in our chemical researches, and the want of uniformity in the results of the multitude of experiments that are daily made, which appear to him to clash essentially with the simplicity of nature. When we consider, he says, the simplicity found in all those parts of nature which are sufliciently known to come within the reach of our obser- vation, it appears improbable that the constituent parts of bodies, which we consider as endowed with reciprocal affinities, should be so loosely united as is often indicated by the most accurate analysis. Hence he is led to conjecture, that in all chemical combinations, those ingredients which are really essential to the compound are but few in number; that they are by nature certain aliquot parts of the whole compound; and that as the aliquot may be expressed by fractions, the denomination of these fractions will always be a small quantity, perhaps never exceeding the number 5.
The author applies this theory to the above-mentioned experiments on calamine; and finding that, with a trifling correction, the results coincide with this theory, he entertains sanguine hopes that future investigations will finally establish it. If so, he thinks that the discovery will introduce in chemistry a rigorous accuracy, of which it has not hitherto been thought susceptible; that it will enable the chemist, like the geometrician, to rectify by calculation the unavoid-
