ON THE AFFINITY OF BODIES 255 



not the property of combining with vitriolic acid in excess, 

 the nitrous and marine acids would neither change vitriolated 

 tartar nor Glauber's salt into acid neutral salts, and there- 

 fore one should never be able to pour off the vitriolic acid 

 from the crystals of nitre ; but it is always combined with 

 fixed alkali, and cannot be separated by any nitrous acid. 



P. 41.1 have great difficulty in believing that caustic 

 volatile alkali precipitates the solutions of lime and lead. 

 Spirit of sal ammoniac is always obtained when that salt 

 is distilled with chalk and water. Simple experiments 

 give sufficient testimony in this case. 



P. 54. Both alkaline salts have not an equal affinity 

 for vitriolic acid. Pour oil of tartar, per deliquium, into 

 a solution of Glauber's salt, and vitriolated tartar will fall 

 to the bottom in the course of a few minutes. 



Pp. 72. and 73. The inflammable air of the zinc and 

 iron should have been taken into the account in the 

 weighing. 



P. 81. This earth of alum can scarce be without 

 vitriolic acid ; for we know that a part of this acid is 

 very difficult to be separated from it ; and on this account 

 it could not attract any fixed air. Were the author to 

 dissolve his earth in distilled vinegar, and then to add 

 a few drops of a solution of terra ponderosa, the vitriolic 

 acid would immediately show itself. 



P. 95. If coals consist of phlogiston and a little earth, 

 where does the quantity of fixed air, which makes its 

 appearance during their decomposition, reside ? This must 

 contribute very much to their weight. 



P. 133. The solution of magnesia becomes a little 

 turbid on the addition of caustic volatile alkali. How, 

 indeed, should it be otherwise ? Since there is formed a 

 triple salt, consisting of the earth, the vitriolic acid, and 



