508 Wisconsin Academy of Sciences, Arts, and Letters. 
acid always formed simultaneously. 9 These facts may have an 
important bearing when we test experimentally the second 
phase of the Walden inversion brought out by Fisher, namely 
the apparent inversion in the action of nitrosyl bromid on the 
amino acid and the normal reaction obtained with ammonia on 
the brom acid to give the corresponding amino acid. In this 
connection, I may add, however, that the action of nitrosyl bro¬ 
mide on alanin gives a quantitative yield of perfectly homo¬ 
geneous, constant boiling, brom-propionic acid. If the inver¬ 
sion which seems to occur with nitrosyl bromide, does not take 
place as a matter of fact, we would simply have to shift the 
names of our aminopropionic acids, i. e. call laevorotatory 
alanin d alanin and vice versa, and likewise other homologous 
amino acids. This would involve no very radical change as we 
now have just such a condition in the case of the halogen suc¬ 
cinic acids—we should have the amino group now and then ex¬ 
erting the same general effect on the absolute rotation of, the acid 
or ester as the substituting halogen group sometimes does. If such 
is the case, we can test the point most readily experimentally by 
a reinvestigation of the action of nitrous fumes on dl alanin to 
determine whether dl lactic acid is really obtained or is the only 
product formed. It is quite reasonable to believe that nitrous 
acid may give in this case also a body having all the properties 
of the acid product which we obtained in the action of moist sil¬ 
ver oxide or dl brompropionic acid. 
Fisher also stated that the inversion seemed to occur only 
with a substituted acids i. e. at the asymmetric carbon atom next 
to the free COOH group and that it took place only with the 
free acid and never with the ester. By substituting C 2 II 5 for 
H in the COOIT group, my own experiments as well as those of 
others have shown that the reactivity of brompropionic acid 
toward oxide of silver in absolute ether solution at ordinary 
temperature is reduced from an extremely high value to prac¬ 
tically zero. By thus reducing the speed of the reaction we 
should naturally expect to get a normal result in the replacement 
of haloegn by hydroxyl using oxide of silver as substituting 
9 Same as No. 8. 
