166 Analysis of Scientific Books. 



expeditiously to his purpose. For 10 : 90 : : 24.88 : 223.92; 

 of which water, 75.12 are already present in the saturated 

 solution. The difference 148.8, therefore, is the quantity of 

 water, that should be added to 100 of the above saturated 



solution, to produce the desired degree of dilution = 



And this rule is immediately convertible into the following 



general form. Let W : S, be the proportion of water to the 



salt in 100 of the saturated solution ; w : s, the proportion 



required in the dilute; then the quantity of water to be added 



Sw 

 to 100 of the former, or x n — W. 



s 



We come at length to his title " Part II. Chemical Exor- 

 mination of Nature" as if the preceding 1500 pages were 

 not a Chemical Examination of Nature. In the first two 

 books, on the Atmosphere and Waters, we can find nothing 

 new, except a Table compiled from " Bladh, Horner, John 

 Davy, and Marcet," of the specific gravity of sea water, iu 

 different parts of the ocean. 



Mineralogy, which begins now to assume the systematic 

 aspect of the other parts of Natural History, by the labours of 

 Werner, Haiiy, Mohs, and Jameson, is here exhibited in a 

 truly chaotic state. He has no allusion whatever to the 

 natural history method of Mohs, which promises to do for the 

 study of minerals, what the sexual system did for plants; 

 enabling a person, on taking up a specimen, to refer it to its 

 peculiar class, order, genus, and species, till he discover its 

 name and various relations. His first chapter, " On the 

 Description of Minerals," is copied from Professor Jameson's 

 Treatise on the External Characters. We find the same chapter, 

 in the same words, in the former edition, but with a reference 

 to Mr. Jameson, which is now suppressed. The only observable 

 alteration, indeed, in his present article on Mineralogy, is the 

 erasure of Professor Jameson's name, wherever it formerly 

 occiuned. 



If the mineralogy be a useless heap of typography, one 

 might have expected some compensation in the chapter " On 

 the Analysis of Minerals." But greater disappointment met 

 us here. The descriptions of the processes transcribed from 

 celebrated analysts, are so meagre and incorrect, as to be 

 most delusive guides to the practical investigator. Under the 

 analysis of sulphuret of silver, of iron, and of molybdenum, 

 we are told that " 100 parts of the dried precipitate, (sul- 

 phate of barytes,) indicate about 14.5 of sulphur." Now they 

 indicate, at utmost, on his own data, only 13.56, a serious 

 difference in modern analysis. In narrating Klaproth's analysis 

 of antimoniated silver, he says, " Common salt occasioned a 

 precipitate which weighed 87.75 (muriate,) equivalent to 65.81 



i 



