184 Philippine Journal of Science 1920 
All of the total nitrogen determinations were made by the 
Kjeldahl-Gunning-Arnold method (22) using 1 gram of copper sul- 
phate instead of mercury, and boiling for four hours(2) after the 
solution turned clear. The Claisen flasks of 1-liter capacity were 
found to be inadequate and 2-liter distilling flasks, modified for the 
purpose, were used instead. In the estimation of arginine Folin’s 
improved absorption tubes(11) dipping into the standard acid 
were used instead of Folin bulbs, and 20 per cent sodium hydrox- 
ide(20) instead of 50 per cent. The absorption tubes were kindly 
loaned by the department of physiology of the College of Medicine 
and Surgery. The amino-nitrogen determinations were made at 
no fixed temperature, since the laboratory of agricultural chem- 
istry of the College of Agriculture has no means for controlling 
this factor. Alizarine sodium monosulphonate was used as in- 
dicator in all of the titrations, and it was found more satisfactory 
than methyl orange. The results are recorded in Table 2, and 
are compared with the analyses of some known proteins in 
Table 3. 
TABLE 3.—Comparison of nitrogen distribution in the hot-water-insoluble 
portion of copra meal with that in some other products. 
— career] 
Lactal- 
pe a Cott Coconut 
Witroces. Guat | Copra | “seea | Coconmt i alins 
weightof, ™el- | meal.c globulin. 
dex- 
trose.b 
eee 
Ami Per cent.| Per eent.| Per cent. | Per cent. a5 
: de “ESE SS SLR a ea a 8.37 25.72 10. 45 7.08 ie 
PE pei earec ke 3.70 7.11 7.78 0.76) *h 
demu nese MACE nee asenegke Ronee 1.05 6.58 0.65 |---------- a5 
— Satiodh GAens bose gS OR GG 8.10 11.73 19.52 32.79 a 
stidine pinebadbitivcennlapec vis sosgtic. 8.22 8.94 6.47 |--------"= Z 4 
Lysine — seein cians wast eeun, Goeuk 12.54 2.19 4S [--a-oe= 45.44 
She Ul ee : 59.09 
7. ORES RENCE 58.79 41.96 42.82 | 460 
TRS Vag eee ees 3.58 2.08 O48 |---< eee 
Suuiiteomers 99.35 | 101.31}  96.90| 100.00 |------""") 
pa nr 
* Gortner, R. A., Journ. Biol. Chem. 26 (1916) 189. 
> The presence of tryptoph kins-Cole 
ane was tested in the water-soluble protein by the Hop 
Hipstass 
Foro: : - S.. Joseph, W. E., and Slater, W. E., Journ. Am. Chem. Soe. 37 casi) 1 
(1914) 490. teal Physiological Chemistry. Philadelphia, P. Blakiston’s Som 
* See footnote 3. 
t Humin absorbed tine 
a 0.11 humin nitrogen in amyl alcohol extract. 
Table 2 shows that the distribution of nitrogen in copra me#! 
is fairly even. As stated . ces 
Seeasgs above, the hot-water-soluble substan 
were eliminated before the copra meal was hydrolyzed pt 
