l60 PHILOSOPHICAL TRANSACTIONS. [anNO }674. 



But these are very weak and inconsiderable, compared with argiinients, 

 which necessitate me to believe, that it emerges from the union of the volatile 

 salt with the oleaginous or sulphureous principle. For, 



1 . There seems to be a great contrariety between acids and alcalies. Being 

 mixed, they heat, contend, and mortify each other; whatsoever one dissolves 

 the other precipitates : whereas, were the salt of alcalies of a nature approaching 

 to acids, they would more plainly unite without that violent contention which 

 usually ensues. 



2. Alcalies and volatile salts agree in most properties, excepting their different 

 degrees of gravitation. They are both diuretical and de-obstruent; they both 

 dissolve sulphureous bodies; agree in their contrariety to acids, but mix toge- 

 ther quietly without noise, heat, ebullition, or impairing each other's virtues, and 

 are easily separable ; the same in quantity and quality they were before mixture. 



3. Tartareous or essential salts of vegetables cannot become alcalies, until 

 their acidity be driven away ; during which operation, the volatile salts and oil 

 uniting, become more ponderous than the acid, which before gravitated more 

 than either of them in their separate state ; so that such a degree of fire, as will 

 wholly dissipate the acid spirit, cannot elevate the more ponderous alcali. Not 

 but that, contrary to what is commonly asserted, the most fixed alcali may be 

 sublimed to great height without additaments, by any intense degree of heat : 

 for I have frequently reduced a pound of it to 3 or 4 ounces, and recovered a 

 considerable proportion, which was caught in well contrived vessels, some yards 

 above the crucible, little if at all altered from what it was immediately before it 

 suffered this violence. On this account chiefly it is, that soot yields some small 

 quantity of an alcali, especially that nearest the focus. 



4. Alcalies may be divided into oil and volatile salt, by easy and natural 

 methods of procedure. I myself have many ways effected this in part; and 

 a very worthy person, in whom I can perfectly confide, assured me, he has 

 frequently resolved the whole body of alcalies into the two distinct substances of 

 volatile salt and oil, receiving of the latter a small proportion ; which is also 

 confirmed by those trials I have made on the same subject. 



I could suggest many more arguments and experiments; but these being suf- 

 ficient, and I think indissoluble, I proceed to confute the pretensions of acid 

 salts to an interest in this new production. First, what concerns tartar, its 

 acidity is driven away in great quantity before it can become alcalisate; and a 

 volatile salt may, to my knowledge, be by divers methods separated from it. 

 Secondly, as to nitre, though that in distillations yields an acid spirit, yet it 

 abounds also in volatile salt, as I could demonstrate from the manner of its 

 generation, and from irrefragable experiments. And besides, perhaps in the 



