I 534 1 
the fame quantity of mineral acid, and by that it is 
more eafily raifed up by the fire than the others. 
By thele obfervations M. Homberg makes evident the 
reafon of fome cafes, difficult to be explained without 
them : as, 'tis well known one ounce of Aqua Regia, 
compounded with the fpirit ot Nitre, and the ammo- 
niac Salt, dillblves twice more Gold than one ounce 
of the fpirit of Salt can Jp. The Chymifts attribute 
that affeft to the foftnelFof the points of one acid, 
and to the hardnefs of the other : when thefe obfer- 
vations make evident that the fpirit of Nitre contains 
twice more of acid Salt than the like volume of fpirit 
of Salt, and open in the fame time the true caufe of 
this effed. - - 
. M. Homberg difcours'd alfo how by the comparifon 
of thefe two Tables we may know the quantity of acid 
Salt contained in an acid Spirit 5 which he • doth in 
the following manner : He takes an acid fpirit (as fpi- 
rit of Nitre) he weighs it by his Areometer, and at the 
fame time he weighs alfo diftilled water (f for the 
weight of the phlegm containd in the acid fpirits is 
like as the weight ol the diftilled water) then he looks 
upon the Tables, where he fees that the bulk of 
fpirit of Nitre compared with a like bulk of di- 
ftilled water, has given a certain quantity of acid Salt 
for each ounce 5 and from thence he concludes, that . 
the bulk of other fpirit of Nitre, of which the 
v/eight is known, compared with the like bulk 
of water, (hall give a determined quantity of acid 
fait, which will be raifed by the computations of the 
relations of the weights of thofe fpirits, with thb 
weights of the like bu Iks of diftilled water, by con^^ 
eluding from them and from the known produd of 
acid fait for the unknown produd of the fame. All this 
will be more explained in the account which w;li 
be infertcd in the Memoirs of the Academy. 
