1823.] Mathematical Principles of Chemical Philosophy. 259 



Similarly, the atomic capacity of carbon is 1*95; twice the 

 atomic capacity of oxygen is 9*5 ; the sum 9*695 ; the atomic 

 capacity of carbonic acid is 2*887 ; i. e. 6*808 is the quantity of 

 caloric evolved. Until we are furnished with the above data, 

 and particularly with the precise relation of electricity to chemi- 

 cal attraction and caloric, it will be vain to attempt to institute 

 any researches into the principles of chemical philosophy ; and, 

 in all computations, tables must be constructed for the atomic 

 weights of bodies in every case. For the table of atomic capa- 

 cities, the argument is, atomic weight x capacities of equal 

 weights. 



Heat evolved by combustion or combination : argument, 

 sum of the atomic capacities of the bodies combined — atomic 

 capacity of the compound. 



. ... atomic weight 



Atomic expansion in volume: argument, — r-j — ~^r> m 

 length, the cube root of the above quantity. 



,-, . 3 / r atomic weight "J c 



Conducting; powers : argument, a / J ^ r— J. tor 



o t «"> ' \/ I specific gravity j 



the lengths of the metallic rods on which the experiment is to 

 be made, in order to obtain the true ratio of the conducting 



powers. 



Article III. 



Abstract of a Memoir entitled " An Attempt to ascertain the 

 Chemical Composition of those Minerals which possess the same 

 Crystalline Form as Pyroxene." By H. Rose. 



(Concluded from p. 231.) 



4. Pyroxenes, with Lime and Protoxide of Manganese as Bases. 



The red silicate of manganese from Langbanshyttan, in 

 Wermeland, Sweden. 



This mineral (manganese oxide silicifere rouge de M. Haiiy) 

 occurs generally only massive on the Hartz, Siberia, Transylvania, 

 and near Langbanshyttan, with a distinct foliated texture identical 

 with pyroxene, which is further proved by an analysis of Prof. 

 Berzelius, according to whom it is a bisilicate of protoxide of 

 manganese combined with some bisilicate of lime. 



The result of his analysis was : 



Silica 48*00 containing oxygen 23*80 



Protoxide ofmanganese 49*04 10*76 



Lime 3*12 0*87 



Magnesia 0*22 



Oxide of iron Trace 



100*38 

 s2 



