284 Dr. Murray on the Chemical Constitution of [Oct 



composed of 100 of sulphur with 150 of oxygen, can be obtained 

 insulated, it might be supposed that the hypothesis of such 

 combinations ought to be excluded ; and that the strict fact only 

 should be admitted, of the two compounds which constitute 

 sulphurous and sulphuric acids. 



There is one ground, however, on Avhich it may be inferred 

 that a relation of sulphur to oxygen, in the proportion of 100 to 

 150, exists. When sulphuric acid is acted on by a base neutral- 

 izing it, its hydrogen combines with a portion of its oxygen 

 forming water. The quantity of oxygen thus abstracted is 50, 

 and, of course, the above proportion remains ; and this being 

 admitted, the existence of oxide of sulphur, it may be supposed, 

 must also be assumed to bring the results under the law of defi- 

 nite proportions ; and the combinations of oxygen to sulphur 

 will still be in the ratio of 1, 2, 3, 4. 



This conclusion, however, does not follow ; for in cases where 

 this apparent result happens, the oxygen which is abstracted 

 forming water is replaced by the oxygen of the base, and makes 

 up the proportion of 200 to 100 of sulphur ; and the new com- 

 pound is a ternary combination of these elements in these propor- 

 tions with the metallic radical of the base. A single example 

 will illustrate this : 30*7 of common sulphuric acid require for 

 saturation 69*6 of oxide of lead; the former is composed of 10 

 of sulphur with 20 of oxygen, and 0*7 of hydrogen ; the latter of 

 64-6 of lead with 5 of oxygen. The hydrogen in their mutual 

 action abstracts 5 of oxygen forming water, and there remain 20 

 of oxygen, 10 of sulphur, and 64-6 of lead in combination. The 

 same result is established in all other cases, and they afford no 

 evidence, therefore, of the existence of any such compound as 

 that of real sulphuric acid. 



But there is another case which does not admit of the same 

 explanation, and in which the relation of 1 of sulphur to li- of 

 of oxygen seems to be demonstrated. It is that of the action of 

 sulphurous acid on salifiable bases. Here, as there is no abstrac- 

 tion of oxygen in the formation of water, while there is the 

 addition of the oxygen of the base, the proportion in the combi- 

 nation is that of li to 1 of sulphur. This will be apparent from 

 the same example of oxide of lead : 20 of sulphurous acid 

 composed of 10 of sulphur and 10 of oxygen combine with 

 69-6 of oxide of lead, composed of 64*6 of lead and 5 of oxygen: 

 supposing a simultaneous combination to be established, the 

 proportions will be 10 of sulphur, 15 of oxygen, and 64*6 of 

 lead ; and supposing the two latter to observe a relation to 

 sulphur, the proportion is that of 100 to 150 of oxygen. 



It might be maintained that no change of composition in the 

 two binary compounds, the sulphurous acid and oxide of lead, 

 takes place, but that they merely unite ; or at least that while 

 the sulphur and lead display their peculiar relation to each other, 

 each of them retains its relation to oxygen. But this is incon- 



