70 ON THE VEGETABLE CHEESE, NATTO. 
precipitate was mixed with mercuric nitrate with the gradual 
addition of small quantities of soda as long as a precipitate was 
formed. This precipitate, after being washed well on a filter, was 
decomposed by sulphuretted hydrogen, and the filtrate evaporat¬ 
ed on the water bath, ammonia being, from time to time, added 
to keep the solution neutral. In the concentrated liquid were 
formed after some time white crystalline masses composed of 
radiating needles of the forms characteristic of tyrosin. They 
were easily soluble in dilute ammonia and in hydrochloric acid, 
slightly soluble in cold, and easily in hot, water. They were 
purified by repeated recrystallisation, and then yielded the reac¬ 
tion of Piria, Wurster and Hofmann for tyrosin . The determina¬ 
tion of nitrogen by KjeldahVs method yielded 7,98%, while the 
theory requires 7,75 %. Also the copper compound was ob¬ 
tained by boiling the solution with copper hydrate and filtering 
while hot. The total quantity obtained amounted to 3.212 
grm. The mother liquor from which the tyrosin was separated 
was farther concentrated and divided into two parts (a) and (b). 
The part (a) was precipitated with phosphotungstic acid after the 
addition of a little sulphuric acid (c) and the filtrate mixed with 
caustic baryta to separate the sulphuric acid and phosphotung¬ 
stic acid. After the removal of the excess of baryta by a current 
of carbon dioxide, the filtrate was evaporated. Numerous 
spherocrystals were obtained with the behavior of leucin mixed 
with the crystals of ammonium nitrate. To remove the latter, 
a little baryta was added and by evaporation the ammonia was 
expelled. When the residue was treated with alcohol, barium 
nitrate remained behind while the alcoholic solution on evapora¬ 
tion yielded crystals of leucin which were converted into the 
characteristic copper compound which yielded on analysis 
1:9.76% copper, while the formula (C 6 H I2 N 0 2 ) 2 Cu requires 19,5%. 
The phosphotungstic precipitate (c) was first washed with 
cold water containing some sulphuric acid and then decomposed 
in the usual way with caustic baryta and the filtrate after remo¬ 
val of the excess of baryta evaporated, whereby a syrupy liquid 
was obtained. I searched here for lysin, lysatinin (both discovered 
by Drechsel) and arginin (discovered by Schulze), which are the 
decomposition products of the proteids of the germinating lupines, 
but all my efforts were in vain. The syrup gave, however, all 
