1S25.] Mathematical Principles of Chemical Philosophy. \\9 



containing oxygen, the atomic capacity is usually greater than 

 that of the base; for instance, the oxides of tin, lead, copper, 

 &c. have a greater capacity than the metals themselves pos- 

 sess ; the increase is not in proportion to the quantity of oxygen; 

 the reason is, that oxygen does not exist in the same state of 

 density in all solid oxides. 



If ,« = weight of base 1 ^^ ^ compound. 

 n = weight of oxygen J 

 a = sp. gr. base. 



b = sp. gr. oxygen as it exists in the compound. 

 c ~ sp. gr. compound. 

 f, n.a.c _ ^f ^j^g oxygen required. 



(m + n).a. - m.c ^^ 



Calculating according to this formula, the sp. gr. of oxygen in 

 glass of antimony is 2-21; in phosphoric acid 5-1?; in oxide of 

 arsenic 1-4; in red lead 3-2; in black oxide of manganese 3- 1 or 

 2-7; in red' copper ore 1-47 ; in iron mica 1'36. Now the most 

 highly electro-negative bodies, or those solids which have the 

 greatest tendency to the earth, have the greatest attraction tor 

 caloric, and the least for oxygen : therefore their capacities for 

 heat are the greatest, and the oxygen is retained with the least 

 force; therefore in the most highly electro-negative combusti- 

 bles, the oxygen retains more caloric than in the electro-posi- 

 tive,' is most easily disengaged, and their oxides act powerfully 

 as supporters of combustion. Thus the oxides of gold, silver, 

 mercury, peroxides of lead and manganese, easily mflame phos- 

 phorus, oxygenate sulphur, and produce other effects which 

 prove that the oxygen retains very much caloric, and it is so 

 easily disengaged, that the three first are reduced by heat alone, 

 and the other two, by the same treatment, part with one atom of 

 oxygen ; while the oxides of iron, tin, zinc, and particularly of 

 potassium, calcium, hydrogen, and other highly electro-positive 

 inflammables, produce no such effects, and are reduced with 

 difficulty, requiring the assistance of other inflammables in addi- 

 tion to heat. When we are possessed of accurate tables of the 

 electrical powers of all the bodies which are supposed to be 

 simple, and of the primary compounds of the capacities for heat, 

 more accurate than any at present existing, and of the true 

 specific gravities, we may expect to arrive at conclusions highly 

 important to science, and which will establish chemical philo- 

 sophy upon a mathematical basis : at present we cannot expect 

 more than the developement of some of the primary laws ot 



The atomic expansions of sohds are in the order of their fusi- 

 bilities ; they are exhibited in the following table : the atcmie 

 expansion =s expansion of equal lengths ^ atomic diameter. 



