6 Sketch of the latest Iviprouemerits [Jxif. 



supporters and combustibles. Those of the one series, according to 

 him, do not combine with those of the other; except sulphur and 

 phosphorus, which combuie both with the metals and alkalies, and 

 therefore constitute, as it were, the Irans'uion from the one series to 

 the other. He endeavours to distribute the bodies in these series in 

 n kind of arithmetical progression, beginning with the most com- 

 bustible bodies, as hydrogen, ammonia, potassium; and continuing 

 to the least combustible, as platinum, rhodium, iridium. If we 

 suppose the series continued farther, we are led to the idea of a body 

 absolutely incombustible. This body naust possess in the highest 

 degree the properties which are the opposite to combustibiiity, and 

 in consequence of the attraction which e.sists between it and com- 

 bustible bodies, it must produce the strongest action, which is that 

 of combustion. This incombustible body, in the present state of 

 our knowledge, is oxygen. 



Between oxygen and iridium the author places carbon, phospho- 

 rus, and sulphur. This last substance, though heat makes it pass 

 into the state of a combustible, ought to be considered as a negative 

 body. 



The products constitute a similar series, wliich commences with 

 the most energetic alkalies, and passes to those which are more 

 feeble, till we come to bodies such as alumina, in which that pro- 

 perty is balanced by the opposite property having the same force. 

 Tiien come bodies of a predominating acidity. This Is at first feeble 

 in the bodies nearest the point of equilibrium, but it becomes of an 

 extreme activity in the bodies at the greatest distance from that 

 point. We see that each series commences with a certain sum of a 

 property, which diminishes in arithmetical progression, and termi- 

 nates by leaving the bodies possessed of the opposite property. 



Two bodies which belong to the opposite extremes of a series 

 combine with great force ; but the energy of this action seems to 

 change their state, since the product of tlie combination no longer 

 belongs to the same order of affinities. The compounds of oxygen 

 and a combustible body pass into the series of products, as likewise 

 do those of hydrogen and sulphur, of tellurium, and without doubt 

 those of various other bodies. The compound of an acid and 

 alkali no longer belongs to the series of products, but to that of the 

 salts. On the other hand, compounds between bodies at no great 

 distance from each other, as between two acids or two alkalies, do 

 rot go out of the series. 



This law embraces all the bodies having the same preponderating 

 forces ; so, however, that these bodies cannot be confounded. It 

 presents, says the author, under a simple expression this truth, that 

 the same force may exist in a state so diiferent that all its attraction 

 for the opposite force will not be sufficient to make it enter into 

 combination. The two most diiferent states are found in the sup- 

 porters and the products. The third state is in the neutral salts ; 

 but they bear a close resemblance to those products tliat are placed 

 tiear the point of equilibrium. Combustibility, then, is the pre- 



