TESTING WHEAT FOB PROTEIN 
11 
Table 5. — The value of catalytic agents on protein test results 
Grams 
used 
Mercury salts 
K2S0 4 and Na 2 S0 4 
CuSCM 
Yellow 
HgO 
Red 
HgO 
HgSCM 
Grams 
used 
K2SO4 
Na 2 S0 4 
Grams 
used 
CuS0 4 
0.0 
.1 
.3 
.5 
.7 
1.0 
Per cent 
100 
102 
104 
105 
105 
105 
Per cent 
100 
103 
104 
105 
105 
105 
Per cent 
100 
102 
103 
104 
104 
104 

3 
5 
7 
10 
15 
Per cent 
100 
103 
104 
104 
105 
105 
Per cent 
100 , 
103 
103 
104 
104 
105 
0.0 
.1 
.3 
.5 
1.0 
2.0 
3.0 
Per cent 
100 
100 
101 
102 
101 
100 
100 
1 1 
1 Low intensity of heat only. 
At low heat copper sulphate has no marked value as a catalyst. 
In fact, large quantities of this reagent reduced the rapidity of 
oxidation. At higher intensities of heat, however, this catalyst seems 
to work well. 
Ten grams seems to be the best weight to use of either sodium or 
potassium sulphate, neither having any chemical advantage over the 
other. In choosing between these two salts as catalytic agents, the 
tendency of sodium sulphate to form an acid cake with sulphuric acid 
must he considered, along with the cost of these two reagents. Unless 
sodium sulphate digests are dissolved in water soon after cooling, 
time will be lost because of the difficulty of getting the salt cake into 
solution. To overcome this, it was found that a mixture of 40 per 
cent sodium sulphate and 60 per cent potassium sulphate will not 
form an acid cake. 
Objection might be raised that a short period of time, such as 
30 minutes, would not be sufficient for the catalysts to exert their full 
effect. To meet this objection, the heating time was extended to one 
hour with two of the catalysts. 
From the data given in Table 6 it is seen that the effect of the 
catalyst was such that it reached its level immediately and remained 
there during the period of the test. From this it can be concluded 
that the full effect of catalytic agents is almost immediate and that 
further breaking up of the protein molecule is due to extended 
heating. 
Table 6. — Influence . of time on 
activities 
of catalytic agent 
S 
Time of digestion 
30 minutes 
60 minutes 
Nitrogen 
as c.c. N/10 
alkali 
Difference 
c.c. N/10 
alkali 
Nitrogen 
as c.c. N/10 
alkali 
Difference 
c.c. N/10 
alkali 
RedHgO: 
0.0 grams _. 
17.25 
17.92 
18.02 
17.97 
17.25 
17.92 
18.04 
18.04 
17.89 
18. 59 
18.69 
18.67 
17.89 
18.58 
18. 58 
18.67 
0.30 grams . - ... 
0.67 
.77 
.72 
0.70 
0.70 grams. - 
.80 
1.00 grams . _ .- 
.78 
Yellow HgO: 
0.0 grams __ " .-__ . 
0.67 
.79 
.79 
69 
0.70 grams ._ -. 
.69 
.78 
