CHEMICAL CHANGES OCCURRING IN OYSTERS. 
T able 1 . Percentages of nitrogen obtained at various stages of handling. 
5 
Date. 
Amino-acid nitrogen. 
Ammoniacal nitrogen. 
Shucker. 
Riffle. 
Commer¬ 
cial 
package. 
Refriger¬ 
ator. 
Shucker. 
Riffle. 
Commer¬ 
cial 
package. 
Refriger¬ 
ator. 
1914. 
Per cent. 
Per cent. 
Per cent. 
Per cent. 
Per cent. 
Per cent. 
Per cent. 
Per cent. 
Oct. 5. 
0.183 
0.166 
0.128 
0.120 
0.00200 
0.0018 
0.0012 
0.0025 
6. 
.173 
.159 
.1267 
.085 
.00189 
.0015 
.0015 
.0004 
8. 
.171 
.1495 
.115 
.146 
.00042 
.0004 
.0000 
.0010 
10. 
.148 
' .149 
.106 
.116 
.00074 
.0011 
.0000 
.0022 
12. 
.155 
.152 
.106 
.089 
.00154 
.0011 
.0004 
.0000 
13. 
.1658 
.1534 
.1183 
.1237 
.0007 
.0006 
.0007 
.00077 
14. 
. 1439 
. 1433 
. 1142 
0007 
.0007 
.00042 
15. 
.1551 
.1512 
. 1232 
.1378 
.00077 
.0003 
.00024 
.00087 
16. 
.1580 
. 1542 
. 1198 
.00038 
0005 
0000 
Nov. 9. 
. 1522 
. 1582 
. 1249 
1272 
0000 
0000 
0000 
10. 
.1484 
.1400 
.1215 
2.0946 
.00032 
.0002 
.00115 
2.00024 
. 1210 
.00017 
11. 
.1703 
.1670 
.1064 
.1232 
.00021 
.00007 
.0000 
.00073 
12. 
.1813 
. 1692 
. 1305 
.00098 
.00021 
.00073 
. 1311 
.00073 
16. 
. 1540 
.00035 
. 1540 
.00035 
17. 
.1932 
.1727 
.1318 
2 .1084 
.00084 
.0002 
.00098 
2.00031 
. 1429 
.00056 
18. 
. 1635 
. 1585 
. 1204 
. 00049 
.00011 
.0000 
21. 
. 1652 
. 1630 
. 1142 
.00014 
. 0000 
.00024 
1.1658 
». 1429 
i. 00053 
L00025 
2 .1170 
2 .00025 
„Dec. 10. 
.1739 
.1558 
.1188 
.1177 
.00014 
.0000 
.00032 
.0000 
11. 
.1456 
.1479 
. 1367 
.1177 
.00035 
.00007 
.00007 
.00011 
12. 
.1702 
.1685 
.1317 
.1250 
.00014 
.0000 
.00008 
.00011 
1 Selects. 
2 Counts. 
From this table it is apparent that a considerable amount of 
amino-acid nitrogen is present in the oyster as it comes from the shell. 
It is probable that a certain percentage of amino-acid, nitrogen exists 
in the tissues of the oyster body, being either absorbed or formed in 
the process of metabolism. Some of this may be due to bacterial 
activity within the oyster itself. 
The comparatively slight washing of the oyster upon the riffle 
board removes approximately 10 per cent of the amino acids present, 
which shows that a certain proportion of them are present in the mucus 
surrounding the oyster. An additional amount of approximately 
25 per-cent is removed in the washing and chilling process proper, 
which may be explained partly by solution in the wash water, partly 
by the fact that most of the remaining mucus as washed from the 
outside of the oyster, and partly by the increase in volume of the 
oyster due to osmosis. 
From the figures in the “Refrigerator’’ column it is seen that the 
relative figures vary widely. In some cases the percentage of amino- 
acid nitrogen apparently increased, in others remained constant, and 
in still others decreased. This variation is due largely to difference 
in stock used, as*it was found impossible, in a large plant, to be sure 
that the oysters stored were from exactly the same stock as those 
analyzed in the preceding columns. However, if the ammo-acid 
content be taken as indicative of decomposition, it is evident that 
