2.950 Observations on the Absorption of  [Ocr. 
under a pressure of 28°46 inches of mercury, only 42°5 of carbonic 
“acid gas ; but when’ the pressure was reduced to 9°37 inches; ‘the 
--absorption amounted to 50:5. 
Exper. 2. Absorption of Gases by’ the adhesive Slate of Menil- 
‘montant.*—I did not introduce this mineral into the fire, because 
it splits, and contracts itself so much as not afterwards to absorb a 
v sensible quantity of most of the gases. A volume of adhesive ‘slate, 
freed from air by means of the air-pump, absorbed, at the tempe- 
erature of 59°, ‘the following proportions of the different gases :— 
Volumes, 
Ammoniacal gas .....eecceesceseee INS 
Carhonié acid. <9) a0 a2 50/0.» = seis toes 
CTE GNIE a "Soin Srpue sian gene his *aeentnaleel 
Tie et ees Kiva fin auecet oehetpel She, «sini tae 
OETEEN she oo 0 a(sik Cleie ceermetersinaye emtien | OTA 
Carbone OXI 6 6.5 )i 5.60 '6t6s Kup Gain hie ay 
Oxy-carbureted hydrogen......-.2+.. 0°55 
Hydrogen . 2 0. oc.cisiesine steele civivisieiele | O48 
These absorptions are still smaller than those by meerschaum, 
and the differences in most of the gases so small that they cannot be 
accurately estimated. Besides, I-must remark that when two gases 
in these experiments appear to be equally absorbed by a solid body, 
this does not entitle us to conclude that they have been absorbed by 
it with equal force. It is much more rational to ascribe the equality 
to the insufficiency of the experiments, which, had they been made 
on a larger scale, would probably have shown some difference. 
Exper. 3, with ligniform Asbestus from the Tyrol and Rock Cork. 
—The ligniform asbestus which I employed resembled splinters of 
nut-wood, and had a specific gravity of 1:42. When heated to 
redness, it lost 0°19 of its weight. The rock cork was white, of the 
specific gravity 0-6 ; and when heated to redness lost 14 per cent. of 
its weight. Both minerals were dried by exposure to a red heat ; 
they were then deprived of air by the air-pump, and at the tempe 
vature of 59° absorbed the following proportions of gas :— 
Ligniform Asbestus. Rock Cork. 
Volumes. Volumes, 
Amimoniacal gas ..4... 12°75 2. cece even BS 
Carbonieracid> 5 4.j:s0ce 4h" ).wicwes srl OBE 
Olefant f.205 02 0.% carer 7% os sii cane 
Carhionic oxide ........ O58" pee UO TS 
Oe. nis» « ore RAE RD (7. AAR gh RRO 
* The specifii> gravity of this stone is 0°95, It is composed, according te 
Klaproth, of : 
Gea ie Ls dels le! Sc Us eels, HOARE sie ve 62°5 
Magnesia’... ....cccencceeccesccevcres 80 
OXiIdE OF ION, «5:00 0.0 0<.c0,0 4.00, ccle baad 4°0 
WWE RLEED < adethser. aide SE LISDS Sots BS ie afelsle'e 22°0 
with some atoms of alumina, lime, and carbon. 
