[ ^13 ] 



ift. Find the difference betwixt the next higher and lower 

 tabular denfities = D, and affo the difference betwixt their acid 

 contents = D'. 



2d. Find the difference betwixt the extratabular fp. gravity 

 and the next upper or next lower, which ever it is neareft to = d, 

 and let the difference betwixt its acid contents (or quantity of 

 real acid) and thofe of the next upper or lower = d\ which is the 



quantity fought ; then as D. D' : : d. d' then d'— -=- — confequent- 



ly d' added to the acid contents of the lower tabular fp. grav. or fub- 

 flraded from the upper, is the quantity fought. 



Note. In general when d, that is the difference between the ex- 

 tratabular fp. grav. and any tabular fp. grav. does not exceed --is-a 

 it is infenfible, and the acid contents of the lower or upper, which 

 ever is neareft, may be afcribed to it. 



Problem 2d. 



The quantity of real acid in 100 parts of an acid liquor being, 

 given but extratabular, being intermediitte between fome of the 

 quantities in the tables^ to find thefp. grav. of fuch acid liquor. 



Find D, D' and d as in the foregoing problem, then </= -^, — « 



then d added to the lower tabular fp. grav. or fubftraded from the 



upper, gives the fp. grav. fought. 



But 



