1819.] Acids, Alkalies, and their Compounds. 283 



second, that of an atom with two atoms ; and the third, that of 

 one with three. To this, however, it may be objected, that no 

 such oxide of sulphur can be obtained ; though, if it were a 

 possible combination, it ought, from the law of atttraction, that 

 the first proportion of an element is retained in union with the 

 greatest force, to be the one most permanent and most easily 

 obtained. 



Whether this objection be just or not, the difficulty can be 

 solved without any hypothesis, on the view that the elements of 

 the supposed water exist in the composition of the acid ; for the 

 quantity of oxygen in this water is just 50 : of course, the entire 

 quantity is the regular proportion 200. And the composition is 

 100 of sulphur, 200 of oxygen, and 6-7 of hydrogen. 



This result favours the conclusion, that the relation of the 

 oxygen in common sulphuric acid is entirely that of this element 

 to sulphur ; that it is, therefore, in immediate combination with 

 the radical ; and hence, that water does not exist in the consti- 

 tution of the acid. And even if the existence of an oxide of 

 sulphur, and of what is called real sulphuric acid, were admitted, 

 the combinations would be strictly conformable to the law of 

 proportions, being those of one of sulphur to 1, 2, 3, and 4 of 



oxvgen. 



The proportion of hydrogen is also determined by its relation 

 to the sulphur, for its quantity is that in which they combine, 

 6-7 of hydrogen with 100 of sulphur, constituting the composition 

 of sulphuretted hydrogen. 



It thus appears that the proportions of both elements are 

 determined by their relation to the sulphur as the radical of the 

 acid, and are those which the quantity of sulphur would sepa- 

 rately require. This, so far as theory can discover, is not a 

 necessary result. The oxvgen and hydrogen might each have 

 required the quantity of sulphur with which they combine ; that 

 is, the existing relations might have been those of sulphur to 

 oxygen, and sulphur to hydrogen, in their several proportions. 

 It is otherwise ; there is the relation of sulphur to oxygen, and 

 in addition to this of hydrogen to the same sulphur ; and thus, 

 since the same quantity of sulphur receives the acidifying 

 influence of both elements, we discover the source of the higher 

 degree of acid power. How water should augment acidity, no 

 principle enables us to conjecture. But how the joint operation 

 of two elements acting on the same quantity of radical which 

 each of them separately is capable of rendering acid, should 

 augment the effect is easily perceived. And even from this 

 consideration alone, there can remain little hesitation in admit- 

 ting the conclusion, that both these elements act directly on the 

 sulphur; in other words, that the three are in simultaneous 

 combination. 



Am there is no proof of the existence of oxide of sulphur, and 

 as no such compound as that denominated real sulphuric acid, 



