( 627 ) 
The name chosen is in agreement with the one formerly used by 
myself and others. 
Aminopropyleneureine hydrochloride which, as already stated, is 
obtained from one mol. of potassium isocyanate and one mol. of 
diaminoacetone hydrochloride in aqueous solution erystallises in beautiful 
small needles which are very soluble in water. Up to the present 
we have not isolated from it the free aminopropyleneureine but have 
prepared a few of its compounds with other acids and also a number 
of other derivatives. 
With the calculated amount of silver nitrate in aqueous solution, 
in the eold, the nitric compound was formed which may be preci- 
pitated by addition of alcohol ; this also forms beautiful small needles. 
The acid sulphuric compound was obtained by treating the hydro- 
chloride, in the cold, with sulphuric acid and removing the hydrogen 
chloride in a vacuum and freeing the residue from the excess of 
acid by means of alcohol and ether. The neutral sulphuric compound 
was prepared from lead isoeyanate and diaminoacetone sulphate and 
was purified by precipitation. with alcohol. 
The four compounds, which have all been analysed, form delicate 
colourless small needles, which have no real melting point, but are 
decomposed on heating at various temperatures. 
When boiled with acetic anhydride and sodium acetate for five 
minutes the hydrochloride yielded a triacetyl derivative, which if 
recrystallised from benzene forms smail delicate needles melting 
at 141°. 
On further boiling, a tetracetyl derivative was obtained, which 
crystallised from alcohol containing a little acetic acid in small, 
beautiful, square plates melting at 168°—164°. 
The composition of these acetyl derivatives is derived from the 
results of the elementary analysis, because acetyl determinations, 
even those according to PerkKiN, did not yield good results. 
The composition of the tetracetyl compound in which, presumably, 
two acetyl groups have entered into the NH, group, and two into 
the NH groups of the ureïne, and which then has this formula : 
CH—N—CO—CH, 
PS 
| i 
C—-N—CO—CH, 
| 
CH,. N (COCH,),. 
is a peculiar one. 
