84 ESSAY V. 



vapours), that is, the phlogiston of the volatile alkali ; and 

 thence arose the elastic fluid ; and the muriatic acid which 

 was before united with the volatile alkali could not now but 

 unite with the phlogisticated manganese. But since this 

 alkali contains more phlogiston than the manganese requires 

 to be combined with, in order to be soluble in muriatic acid 

 (for nitrum flammans will deflagrate, but not a solution of 

 phlogisticated manganese in nitrous acid, after being 

 evaporated to dryness), the rest of it combines with 

 another portion of the manganese, which, being thus 

 phlogisticated, causes the alkali to go over in a caustic 

 state, for the reason assigned in Sec. xxxix. (b) ; and thus 

 it likewise appears whence the air-bubbles come which are 

 obtained from caustic volatile alkali (Sec. xxv. (1)), viz. the 

 dephlogisticated marine acid in this process combines, in 

 consequence of its great attraction for phlogiston, with that 

 of the volatile alkali, and thus a part of this salt is neces- 

 sarily decomposed. 



SECTION XL. EFFECTS OF AESENIC, OKPIMENT, AND 

 ANTIMONY. 



(a) Powdered manganese, mixed with an equal quantity 

 of arsenic, was distilled, when all the arsenic came over, and 

 the manganese remained behind unchanged. (&) Manganese, 

 distilled with an equal quantity of orpiment, yielded some 

 volatile sulphureous acid, which was followed by a small 

 portion of yellow sublimate, and at last a little red sublimate. 

 I increased the fire by degrees, till the retort began to melt ; 

 but the orpiment remained attached to the manganese, (c) 

 The same thing happened when manganese was treated with 

 an equal quantity of antimony, which likewise yielded a 

 pungent sulphureous acid, but no sublimate. In this 



