ig 6 Dr. Marcet on the specific gravity and temperature 
to show how the various statements which it contains may be 
reduced to the form in which analytical results are usually 
expressed. 
Thus, for instance, if we select the water marked No. 27, 
which was taken up nearly in the middle of the North Atlantic, 
and the specific gravity of which was 1028.86, 500 grs. of 
this water yielding 21.3 grs. of saline matter, dried at 212 0 , 
we shall proceed in the following manner : 
The muriate of silver obtained from 500 grs. of the water 
being 42 grs., 100 grs. of which are equal to 19.05 of dry 
muriatic acid, the 42 grs. of luna cornea will be equal to 
8 grs. of muriatic acid. 
The sulphate of barytes obtained from a similar portion of 
water being 3.85 grs. dried at 212 0 = 374 grs. dried at a red 
heat,* 100 grs. of which contain 34 grs. of sulphuric acid, 
the quantity of dry sulphuric acid in 500 grs. of the water will 
be ( 100: 34: : 3.74: 1.27) 1.27 grs. 
The oxalate of lime, from a similar portion of water, being 
0.8 grs. dried at 212 0 ; and 100 parts of oxalate of lime so 
dried being = o.3i4*f* of pure lime, the quantity of lime in 
500 grs. of the water will be be 0.314 grs. 
The phosphate of magnesia being 2.7 grs., 100 of which 
contain 40 of magnesia, the quantity of magnesia in 500 grs. 
of the water will be 1.08 grs. 
It appears, therefore, that the quantities of acids and earths 
* I found by a careful experiment, made for the express purpose, that ioo grs. of 
^ulphate of barytes, dried at zi 2°, were reduced by a red heat to 97.2 grs. 
f I obtained this result from a direct experiment, in which 24 grs. of ignited 
muriate of lime = 12.24 grs. of pure lime, gave 31.2 grs. of oxalate of lime dried 
at 212 0 . Therefore, 31.2 : 12.24 :: 100: 39.23. 
