DISTILLATION OF LACTIC ACID. 
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it is a solid, amorphous, brownish yellow mass, which melts 
even below the boiling point of water, becomes tenacious 
on cooling so as to be drawn into threads, possesses an ex- 
cessively bitter taste, and dissolves in every proportion in 
spirit and in absolute alcohol. From this solution the an- 
hydrous acid is precipitated by water in flakes, which gradu- 
ally unite into drops. By prolonged boiling with water, or 
by long standing exposed to a moist atmosphere, the anhy- 
drous acid is reconverted into the ordinary state. This 
metamorphosis is very quickly effected by treatment with 
alkalies and alkaline earths. The anhydrous lactic acid 
maybe exposed to a temperature of 464° F. without expe- 
riencing any change ; decomposition begins at 482° and is 
complete at 500°. The products of decomposition (at 500°) 
are carbonic oxide, with about 3 to 4 per cent, in volume 
of carbonic acid ; further, aldehyde, lactic and citraconic 
acid, with which is mixed some reproduced lactic acid; no 
hydrocarbons were found among them, nor could any lac- 
tone or acetone, stated by Pelouze to occur among these 
products, be detected. From 1 to 2 per cent, of carbon 
remained in the retort. 
When, in order to separate these substances, the distillate 
is mixed with water, aldehyde and hydrated lactic acid dis- 
solve, whilst another portion sinks to the bottom as a 
transparent, yellowish, and at first very mobile oil. When 
left for some time in contact with water, the amount of the 
oil gradually decreases, and in the course of a few days it 
has entirely disappeared, leaving behind a few smeary 
crystals, which likewise dissolve in the course of time. This 
results more rapidly when a large quantity of water is 
added, and the whole well shaken or heated. The oil con- 
sists of lactide, citraconic acid, and some hydrated lactic 
acid. That no anhydrous lactic acid distils over as such is 
proved from the fact, that when the contents of the first 
recipient are allowed to solidify, and are then treated with 
alcohol, which leaves the lactide undisssolved, no lactic 
acid is precipitated by water from the alcoholic solution, 
