VOL. XXir.] PHILOSOPHICAL TKANSACTIONS. 485 



By this table it appears that all liquors, and even mercury itself, are condensed 

 and rarefied in cold and hot weather. 



For the quantity of the volatile acid salt contained in the acid liquors, M. 

 Homberg declared first what he means by this salt, and says, the acid spirits are 

 no other than a salt dissolved by a little water, its taste and effects showing 

 it to be an acid. He calls it volatile, because it is raised by the fire with the 

 phlegm, and it can hardly be separated from it, and reduced in a dry form. He 

 has shown the way to know the quantity of salt contained in a determined 

 quantity of acid spirit, viz. by the weight of its volume compared with the weight 

 of another spirit, of which the quantity of salt contained in it was known, 1st. 

 he poured on an ounce of salt of tartar well dried ; as much acid spirit as the salt 

 of tartar could take up ; then he evaporated all the insipid phlegm out of this 

 salt, and he weighed the matter ; the quantity of its weight, above the weight of 

 the salt of tartar before saturation, is the quantity of acid volatile salt contained 

 in the quantity of acid spirit which has been taken up by one ounce of salt of 

 tartar. Here is the table of the quantity of acid that has been necessary to the 

 perfect impregnation of the salt of tartar; and by the same means the table 

 of the quantity of acid volatile salt, contained in one ounce of several acid 

 spirits. 



For the perfect impregnation of 1 oz. of salt of tartar, there was poured on 

 it 1 oz. 1 dr. 36 gr. of spirit of nitre ; the weight of that salt after the evapora- 

 tion of the insipid humidity was increased to 3 dr. lOgr. above 1 oz., that in- 

 crease from the acid remaining in the salt of tartar, shows that 1 oz. of spirit of 

 nitre contains 2 dr. J 8 gr. of acid salt. — So for the impregnation of an ounce of 

 salt of tartar there was poured npon it 2 oz. 5dr, of spirit of salt, and the in- 

 crease after the evaporation has been found 3 dr. 14 gr. and therefore 1 oz. of 

 spirit of salt contains 1 dr. 15 gr. of acid salt. — Upon an ounce of salt of tar- 

 tar was poured 3 dr. of oil of vitriol, and the increase was found 3 dr. 5 gr. ; 

 therefore an ounce of oil of vitriol contains 3 dr. 15 gr. of acid salt. — Upon an 

 ounce of salt of tartar was poured of aquafortis 1 oz. 2 dr. 30 gr. the increase 

 was found of 3 dr. 6gr. ; therefore an ounce of aquafortis contains 2 dr. 26 gr. 

 of acid salt. — Upon an ounce of salt of tartar has been poured of distilled vinegar 

 14 dr. the increase was found of 3 dr. 36 gr. ; therefore an ounce of distilled vine- 

 gar contains 18 gr. of acid salt. 



It appears by this table, that the quantity of acid salt for saturating the salt 

 of tartar is nearly the same, though the quantity of acid liquors should be very 

 different; it is only the acid of vinegar of which the salt of tartar retains more 

 than it does of the others, that M. Homberg attributes to the subtilty of the 

 particles of the vegetable acid, which have been very much divided by the alte- 



