46 E. Hitchcock on Fossil Footmarks of the Connecticut Valley. 
The boiling point of amy of ethyl is 159°, and its p 
erties correspond with those of the liquid obtained above; t 
slight difference in boiling siniae and composition arises without 
doubt from traces of acetate which the liquid still contained. 
The portion which dissolved in water was a strong acid; the 
solution, neutralized with carbonate of lead and evaporated over 
sulphuric acid, gave large and well formed crystals, whose form 
and angles, measured with a hand goniometer, corresponded to 
those described by Gerhardt as belonging to acetate of lead. 
The double decomposition which takes place here is represented 
by the equation :— 
Acetate of ethyl. Bromacetic acid. Bromacetate of ethyl. Acetic acid. 
cH 0 rs Ca aBrOg es if: Colts, 
The decomposition of acetate of sihyl by bromine is analo- 
gous to that which Mr. Gal* has observed with anhydrous aceti¢ 
acid and chlorine :— 
Anhydrous acetic acid. Chloracetic acid. Chiorid of acetyl. 
€244290 per es MEG 4 028,00 
pee ide reaction is another among the many which tend to de 
monstrate the close analogy existing between the composition 
of the ethers and that of the anhydrous acids. 
Paris, 
a 
Art. Vil—New Facts and Conclusions respecting the Fossil Foot 
marks of the Connecticut Valley; by Epwarp Hrrcxcocs. 
I HAVE devoted a considerable time during a few years q 
to the preparation of a Descriptive Catalogue of the Fossil Foot — 
marks in the large collection of Amherst College. Moreover, 4 
| Canis py “i 570. 
