\ 
APPENDIX. MODIFIED by COMPRESSION. 183 
Tuts view derives fome confirmation from an infpection of 
Columns VI. and VII.; the firft of which exprefles the abforp- 
tion ; and the fecond, that refult, reduced to a per centage of the 
original weight. It there appears, that whereas chalk abforbs 
23-97 per cent., fome of our refults abforb only 0.5, or fo low 
as Q.11 per cent. So that the power of abforption has been re- 
duced from about one-fourth, to lefs than the five hundredth of 
the weight. 
I nave meafured the diminution of bulk in many cafes, par- 
ticularly in that of No. 11. The chalk, when crude, ran to the 
75th degree of WEDGwoop’s gage, and fhrunk fo much during 
the experiment, that it ran to the 161"-; the difference amount- 
ting to 86 degrees. Now, I find, that WEDGwoop’s gage tapers- 
in breadth, from 0.5 at zero of the fcale, to 0.3 at the 240th 
degree. Hence, we have for one degree 0.000833. Confequently, 
the width, at the 75th degree, amounts to 0.437525; and at 
the 161ft, to 0.365887. Thefe numbers, denoting the linear 
meafure of the crude chalk, and of its refult under heat and 
compreflion, are as 100 to 83.8; or, in folid bulk, as 100 to 
57-5: Computing the denfities from this fource, they are as 
Ito 1.73, The fpecific gravities inthe Table, of the chalk, and 
of this refult, are as 1.551: 2.435; that is, as 1 to 1.57. Thefe 
conclufions do not correfpond very exactly; but the chalk em- 
ployed in this experiment, was not one of thofe employed in de- 
termining average fpecific gravity in the Table; and other cir- 
cumftances may have contributed to produce irregularity. 
Comparing this chalk with refult fecond, we have 1. 551: 2.575 
fo I: 1.6602. 
TABLE 
