3884 M. Lautemann on the Formation of Propionic Acid. 
Lactic acid is regarded by Kolbe as oxypropionic acid, that is, 
as propionic acid in which an atom of hydrogen in the radical is 
replaced by peroxide of hydrogen, just as chloropropionic acid is 
propionic acid containing an atom of chlorine in the place of an 
atom of hydrogen. 
C§ H5 = 02 C5 HAC Ht 02 C5 H4 (HO?) 1 YO? 
Propionic acid. Chloropropionic acid. Oxypropionic acid. 
In accordance with this view it might be expected that if hydro- 
gen could be directly substituted for the group HO®, propionic 
acid would be regenerated, and this mode of regarding lactic acid 
would receive additional support. Lautemann* has made a 
series of experiments in this direction. 
The change is not effected by treating lactic acid with sodium, 
or with sodium amalgam, nor with electrolytic hydrogen; but 
it takes place by means of hydriodice acid. When lactic acid was 
saturated with hydriodic acid gas, a separation of iodine com- 
menced almost immediately ; to complete the change, the solu- 
tion was heated in a closed tube to 140°. The contents of the 
tube were then distilled with sulphuric aeid ; the distillate, which 
contained hydriodic acid and free iodine, was treated with car- 
bonate of silver, and filtered. On cooling, crystals separated 
which had the appearance and all the properties of propionate 
of silver. The change is thus expressed : 
C® Hé 0° + 2HI=C® Hé 044+2HO+2I 
Lactic acid. Propionic acid. 
Regarding alanine as amidopropionicacid, C° H* (NH?) ne 02, 
or propionic acid in which an atom of hydrogen in the radical is 
replaced by the group NH?, a view rendered highly probable by 
the investigations of Perkins, Cahours and Ulrich, and regard- 
ing lactic acid as oxypropionic acid,—it is obvious to expect 
that lactic acid may be transformed into alanine, as Strecker has 
shown that alanine may be transformed into lactic acid. Kolbe + 
has effected this in the following manner :—By treatment with 
pentachloride of phosphorus, lactic acid is changed into chloride 
of chloropropionyle ; by treating this with absolute alcohol, it is 
changed into chloropropionic ether. This is then heated with 
ammonia in a closed vessel to 100°, the contents of the vessel 
evaporated and exhausted with absolute alcohol, by which the 
greater part of the chloride of ammonium is left undissolved. It 
is then boiled with water to expel the alcohol, and subsequently 
with oxide of lead, which decomposes the rest of the chloride of 
ammonium, forming with the chlorine a basic chloride of lead, 
* Liebig’s Annalen, February 1860, 7 Ibid. 
