RR ee eee 
ea we 
‘ 
} 
= 
4 
4 
Chemistry and Physics. 249 
evolved in the Saee of the two anhydrous compounds. Thus 
We know from previous investigations that 3(K,+ Br, 
+ KBr+ Aq. yield... . : _- +285 0 units, 
We find by experiment at this time that Al, Cl, dis- 
solved in the previous solution yield. - 
Papreseniing the heat resulting from the union of 
Al,+Cl,=Al,Cl, by 
We have for be ‘Cl, +-OR Brag oF ee +3610 “ 
So also we know that 3(K,+Cl, ee 
Aq. yield - -+3024 “ 
And we find a as before that Al, Br, dissolved in this 
product yields -_- .-+ 869 “ 
Roureondng the heat-form Al,+ Br, = Al Br, py-- -Yy 
We Had for Al, Br,+6KCI+ Aq. .--..----. +3893 “ 
eed 
the final states of the two regulting ye eee seem abso- 
ae the same, it must be that 
ie 861 O=y+389'3 
— ¥=389'°3—361°0=28°3 units. 
If then we ate for x (when Al,4Cl,=Al,Cl,)-+160°9 
We have for y (when Al,+Br, =Al Br,) Bde 
of alcohols by the oe acid has long been known, and the 
theories any anys to explain this so-called “ catalytic ” action 
have been numerous. In a paper following the last, Berthelot 
seeks @ shag that these arin Iso conform to the general 
“law aximum works,” that is, are the natural result of a 
ditions, involve d in both the separate and also Lp mutual action 
of h hydr ochloric and acetic acids on alcohol are fully flee 
and it is shown that in the last case the Sle of acetic et 
is attended with a much greater evolution of heat than ecula Bi 
that of herds nelieria ether. Hence when the two acids are pres- 
ent, the former and not the latter of these two ethers is the chief 
