442 
the smaller the concentrations used. On the other hand the difficulty 
of accurately determining very small lengthenings of curdling-time, 
citrate-concentration 
0.001 0.002 0.003 0.004 
forms another limit. The best concentrations proved to be 1/125 N 
and 1/25N; citrates im this concentration practically inhibit milk- 
eurdling, while indifferent salts as sodium chloride, sodium formiate 
among others show none or very little influence. 
In order to find ‘the influence of salt on milk-eurdling, 1/80 gram- 
molecule *) of the acid was neutralized with titrated natron, with 
addition of two drups of litmustincture till the colour was the same 
as distilled water with the same quantity of indicator. 
Then the volume was brought to 50 ec. with distilled water. In 
this way a neutral solution was obtained, containing */, grammolecule 
of neutral salt per liter. In the same way or by diluting the '/, N. 
solution */,, N. solution of the neutral salts was obtained. 
The curdling-time was determined as described above; only 2 e.c. 
of the salt was added instead of the 2 ec. of distilled water. After 
') Not 1/80 equivalent, but 1/80 molecule; therefore of a tribasical acid with 
mol. weight 200 —— gr. were dissolved. 
Lo 
