1815.] in (he Physical Sciences. 7 



ponderance of the positive force in a particular state, which M. 

 Oersted calls the state of supporters, or of the first class of bodies. 

 Alkalinity presents the same force, but in a different state, which 

 he calls the stale of' products, or of the second class. We do not 

 know the nature of this difference, but we know that it exists, and 

 that the forces are in a state of greater liberty in the first class than 

 in the second. 



Combustion sometimes gives us alkaline products, sometimes 

 acid, and sometimes neutral ones. The product, by combining 

 with oxygen, loses either in part or entirely its free positive force, 

 and passes to the order of bodies of the second state. The same 

 thing happens to the negative force of the oxygen. If the body be 

 combustible in a high degree, and does not combine with too much 

 oxygen, the positive force still preserves the preponderance, and the 

 body is alkaline. If, on the contrary, the body be but little com- 

 bustible, and combine with a great deal of oxygen, the negative 

 force remains preponderant, and the body is acid. 



In oxygenated bodies we find of necessity a combustible body and 

 oxygen united together, and constituting a body of the second class. 

 Hence we must conclude tliat these bodies unite together the two 

 opposite properties, the alkaline avid acid, one of which is often 

 rendered insensible by the other. However, in a great number of 

 other combinations, both properties subsist together. This is the 

 case in the oxides of lead, copper, &c. In some bodies we find the 

 jK)sitive or negative force in both states at the same time. Thus 

 ammonia possesses bolh tlie positive force of the first class and that 

 of the second; while the nitric and oxymuriatic acids possess the 

 negative force both of the first and second class. This is tha 

 natural effect of a combination, either feel)le or far from the point 

 of saturation, by which a force is reduced to an inferior state. In 

 the combination of tellurium with hydrogen, the negative force of 

 the metal is sufficicnlly changed by tlie positive force of the 

 hydrogen to occasion a state of acidity. The positive force con- 

 tained either in the hydrogen or in the tellurium has not suffered 

 enough of change to come to the state <jf acid. Hence we find ih 

 tellureted hydrogen gas a strong combustibility, and a very distinct 

 acidity, existing together. 



It is well known that electricity produces heat. M. Oersted 

 ascribes this effect to a union between the two opposite electric 

 forces ; and it is so much the more intense, the greater obstacles the 

 tiansmission of the electricity meets with, provided that these ob- 

 stacles may be overcome. The transmission of electricity consists 

 in a series of attractions and repulsions, or in the undulatory move- 

 ment experienced by the peculiar forces of the body. Chemical 

 union between electro-negative and electro-positive bodies excites 

 always heat, and none of the electrical forces escapes in a state of 

 liberty. However, the increase of conducting power may coimter- 

 bidance this eH'cct, and even overcome it, and then cold is excited, 



'J'herc exists three principal combinations between the electrical 



