130 ON THE PRODUCTION OF VALERIANIC ACID. 
with acids. The mother-ley from which this hody crystal- 
lizes yields, on further evaporation, a considerable quantity 
of leucine. When the fused mass is supersaturated with 
tartaric acid instead of acetic acid and the liquid submitted 
to distillation, an acid product is obtained, which on satura- 
tion with barytic water, evaporation to dryness, and sub- 
mitting the dry barytic salt with phosphoric acid to distilla- 
tion, yields a colourless oily acid and an aqueous oily fluid 
possessing the odour and all the properties of valerianic 
acid. Leucine yields, on fusion with hydrate of potash, 
ammonia and hydrogen ; the residue contains valerianate 
of potash ; the formation, therefore, of the leucine appears to 
precede that of the valerianic acid when caseine is fused 
with potash. To within 1 equivalent of hydrogen the for- 
mula for leucine expresses the composition of an aether 
consisting of 1 atom cyanic acid, 1 atom oxide of amyle and 
2 atoms water. By passing the vapour of the hydrate of 
cyanic acid into anhydrous fusel oil, a solid crystalline sub- 
stance, soluble in water, is obtained, which readily crystal- 
lizes from this solvent, and in external appearance has the 
most striking resemblance to leucine, from which, however^ 
it differs by its solubility in aether. 
When the fusion is continued for a longer time, a consi- 
derable quantity of butyric acid is obtained along with the 
valerianic acid. The silver salt, prepared with the oily 
valerianic acid from caseine, left on combustion 51-62 silver 
so that its identity with the ordinary valerianic acid cannot 
be doubted. The crude distillate contains, besides valeri^ 
anic acid, a volatile substance of the odour of human feeces } 
which reduced the nitrate of silver, but contained no formic 
acid ; a quantity of the oxalate of potash separated from the 
alkaline ley previous to its being supersaturated with tar. 
taric acid. 
I have not observed in the treatment of caseine with 
potash, any protide and erythroprotide, names given by 
Mulder to two smeary syrupy bodies, which he obtained in 
