313 
gas in a volume nearly fourteen times greater than 
that of the charcoal. Morozzo again resumed his 
experiments, with the precautions employed by 
Rouppe, and, upon the whole, obtained results 
nearly similar to those of his former trials. During 
this remarkable attraction and condensation, the 
elastic fluids appear to suffer no change in their pro- 
perties, but are again expelled unaltered by low de- 
grees of heat ; neither does the charcoal itself suffer 
any change, except from a small increase of weight. 
This attraction of gases by charcoal, says Mr Mur- 
ray, can scarcely be denominated chemical affinity, 
but the union between the gas and charcoal must be 
regarded as rather of a mechanical nature. Gases, 
indeed, are thus condensed, to which, under any 
known circumstances, charcoal does not exert any 
chemical attraction ; and they are all reproduced 
pure by a slight elevation of temperature *. 
612. The foregoing experiments, thus repeated 
and varied by so many different philosophers, and 
which, as to their general results, are not easily ex- 
posed to deception, are nevertheless pronounced 
" vague and contradictory" by Mr Dalton, who seems 
inclined entirely to discredit them, and that too upon 
the faith of the following experiment. He made 
1500 grains of charcoal red hot, then pulverized it, 
and put it into a florence flask, with a stop-cock ; 
to this flask, a bladder, filled with carbonic acid, was 
connected, and the gas was then admitted into the 
flask, which became a little heavier. During the ex- 
Syst, Chem. vol. ii. p. 317. et seq. 
