Chemistry and Physics. 261 
alkaline cinnamates, cuminates or salicylates, the oxychlorid of benzoyl 
produces what may be termed double acids, that is to say, compounds 
of two anhydrous acids. These are oily liquids, inodorous and insolu- 
ble in water, but rapidly converted by boiling water into mixtures of 
the hydrated acids. nhydrous acetic acid is obtained by heating the 
oxychlorid of benzoyl with an excess of fused acetate of potash. It is 
a perfectly colorless mobile liquid, highly refracting and possessing a 
very strong odor analogous to that of glacial acetic acid but more 
powerful. [t boils at 187° C.: it is heavier than water with which it 
does not mix; by long agitation, however, with water, or by gentle 
heating, it is dissolved and converted into ordinary acetic acid. By the 
action of the oxychlorid of phosphorus upon the acetates, Gerhardt has 
identical in principle with that used by Williamson in preparing his new 
alcohols. The same questions arise in this case as in the case of the 
alcohols cited. Gerhardt doubles the formulas of the anhydrous acids 
which he has discovered, and unites them (in the ordinary equivalents) 
C2sH1006 and CsH6Oc, or using his own equivalents, C14 
CsHcOs. The whole question of the constitution of the new compounds 
depends upon this: can a given molecule unite chemically with another 
molecule of the same species so as to form a third molecule of a differ- 
ieve, no means of answering 
oO 
os 
[ 
i 
~— 
oO 
2. 
i") 
“a 
~w 
ae 
i 
oO 
= 
oO 
$=*) 
= 
o 
o 
as 
g 
o 
Da 
o 
o 
-— 
~ 
< 
oO 
and the anhydrous inorgani¢ acids as SOs an Os.—w. &. ; 
5. Equivalents of Sulphur and Barium.—Strvuve has determined 
the equivalent of sulphur by reducing sulphate of silver by hydrogen. 
6001 which confirms 
e 
determined the equivalent of barium by decomposing the chlorid of 
rium by sulphuric acid, and weighing the resulting sulphate. As a 
mean of two experiments he obtained the. number 68°13 or 851-62.— 
Ana, der Chemie und Pharmacie, |xxx, W. G. 
6. On the Corrosion of Lead by Galvanic action; by R. Buckter, 
(from a letter to the mats dated Baltimore, July 16th, 1852.) —I am 
perfectly aware that the corrosion of lead by galvanic action, induced 
i nown fact 
8 
tae recently oecurred here, which demonstrates clearly the im- 
Propriety of connecting lead with another metal under water. A gen- 
