242 REPORT OF THE CHEMIST OF THE 
during decantation. The flasks with contents were weighed after 
decantation in order to find how much free acid solution adhered 
tc the casein particles and the walls of the flasks; the amount 
varied from 2 to 4 cc. To the casein left in each flask there were 
then added ivo cc. portions of pure water, and the mixtures were 
shaken for the different periods of time, one minute to five hours, 
as indicated in Table XI, column J. They were then filtered again 
(filtrate 2). The amount of acid in each filtrate was determined 
by conductivity measurements. From the first filtrate were obtained 
the data necessary to determine how much acid had been taken 
up by the casein to form the insoluble acid-casein, when shaken 30 
minutes with acid. From the second filtrate were obtained the 
data required to determine the amount of acid extracted from the 
insoluble acid-casein by treatment with pure water for the different 
periods of time given. The results were corrected for the amount 
of casein that escaped by decantation and also for the amount of 
free acid that remained adhering to the casein and the flask at 
the first filtration. The detailed results of the work are given 
below in Tables X and XI. 
e 
TABLE X.— SHOWING AMmouNTS oF AcID TAKEN UP By CASEIN, WITH CORREC- 
TION FAcTors. 









A B c D Ey. | F G H 
PM HH RCE oP bee wy hed ey MEY tH : os 
gS2 bow? | 3 Gm» | seed) SP | won 
et Oe ea l= as eRe B > > 3g Ou 4 5% 
os MS) = no salt! ba Oo St a3 a bd 
L No. or Expsri- [BEZ~ |3o4, MO) ge | eo |Se8a|] 820 | Sem 
MENT. 8.8 2e1 8" “aa Gab oeS LT ats 2 aoe 
q . fo} . cr on —_ ‘— 
BEPSs|SeRees| B23 | 22a |“22s) gus | 288 
salad gal aoc sou aon gos ga gate 
oO oO 6) Oo oO oO oO 
Ocand itera ee 956* 102.6 .0164 .9836 100.9 3.55 ae) 
7 TERPS SRT C .959 102.3 .0074 .9926 IOI.5 3.44 3.30 
Se ae ee ete eee .964 101.8 .0165 .9835 100.1 3.38 3.26 
NF oie PaMerehe latte bral ae 971 101.0 .0100 .9900 100.1 4.81 4.67 
Hae aot bs a rin te teeta es .958 102.4 .0080 .9920 101.6 3.24 oLLo 
OPA eran aera 955 102.7 cae .9857 101.2 3.5% 342 
43 ote. ° 




* The concentration of the acid used was 1.982 before contact with casein. 
