McLeod—The 'Walden Inversion—A Critical Review. 519 
That dilactic acid is not present is shown by the fact that the 
crude acid product obtained by the action of silver oxide on dl 
brompropionic, although proved to he homogeneous, shows no 
tendency to crystallize. In addition brucin dilactate was found 
to have dec. pt. l,10°-138 o while the brucin salt of the crude 
acid gum melts 200 o -212° very similar to that of brucin lactate, 
and other high melting brucin salts. 
From the standpoint of dissociation according to 1STef, car- 
boxyethylidene is formed first as intermediate product. By 
subsequent addition of unchanged brompropionic acid we should 
expect as the ultimate product not dilactic acid but its structural 
isomer which exists in two space isomeric modifications: 
CH 
HCBr '- > 
O OH 
CH 3 
Cc^+HBr 
I 
COOH 
ch 3 ch 3 
2C(+2 HC— Br- 
COOH COOH 
CH 3 
> HC — 
CH 
CH 
i 
C—Br+ Br C 
I_ I 
CH 3 
CH 
OOH COOH 
COOH COOH 
ch 3 
iooH 
CH- 
C — Br + AgOH 
COOH 
> HC 
CH- 
I 
ch 3 
<L 
I 
OH + Ag Br 
OOH COOH 
Work is now being continued along this line by the author of 
this article in the chemical laboratory of Beloit college. (An at¬ 
tempt will be made to prepare this body synthetically and study 
its properties. From its structure we should expect it to behave 
very similar to lactic or dilactic acid and in addition it ought to 
give very readily a 1, 2 lactone. 
In conclusion, I will say that, by using absolute ether in 
place of water as solvent, one is enabled to study the action of 
silver oxide on the simple esters of the halogen substituted fatty 
acids without danger of hydrolysis. In marked contrast to the 
behavior of the free acid, dl brompropionic ester does not react 
at room temp, with silver oxide in absolute ether solution. By 
