5) 
Classification of simple Bodies. 448 
for chlore ought not, in the eyes of the chemist who has precise 
ideas as to the action, equally energetic at least with that of oxy- 
gen, which it exercises on the metals, to be regarded as a cha- 
racter less important than the degree of affinity for oxygen; and 
‘the chlorure of gold is decomposable by heat; whereas that of 
silver, kept free from the contact of water and hydrogen, is ab- 
solutely unalterable at the highest temperature. 
Here therefore we have two motives nearly equal, one for. 
uniting and the other for separating these bodies. In order to 
resolve this difficulty, it is indispensable to have recourse to other 
properties; those of their oxides and their salts which they form 
with the acids, are then exhibited naturally, and decide the 
question, by showing us that the supposed analogy hetween those 
two metals is not confirmed by the resemblance of their principal 
characters. In fact, the oxide of silver is very alkaline, a little 
soluble in water, and completely saturates the acids: the oxide 
of gold presents nothing similar: and this difference, added to 
some other properties, less important, it is true, which silver 
presents in the metallic state, places this body with lead near 
potassium and sodium, and consequently very far from gold. 
Since precise notions have been acquired as to the nature of 
chlore, several chemists have ceased to give to the properties 
which depend on the affinity of simple bodies for oxygen, an ex- 
clusive preponderance ; but then one too great -has been given 
to the assimilation which has been made of oxygen and of chlore, 
It has been attempted to arrange all the simple bodies in two 
classes, independent of each other, under the names of comlusti- 
ble bodies, and supporters of combustion.’ ‘This division has had 
the same inconvenience with that of the metals and the non- 
metallic bodies, by making us mistake the analogies of bodies 
which it places in different classes. This inconvenience has 
even been the more injurious to the theory of chemistry, in as 
much as it has taught us to neglect analogies much more com- 
plete and more striking than those which the separation of the 
metals and other simple bod:es had caused to be neglected. Such 
are the analogies of the chloric and iodie acids with the sulphuric 
and nitric acids, of the chlorates and the iodates with the ni- 
trates, and particularly that of chlore and iode with sulphur, 
greater still than the analogy of the same bodies with oxygen. 
The combination of those four substances with the metals to 
which they strongly adhere, takes place by occasioning a greater 
or less extrication of heat, and frequently of light: the com- 
pounds which result present a crowd of common properties: 80 
far there is no occasion to approximate more particularly chlore 
and iode to oxygen than to sulphur; but this last forms like 
iode 
