CHEMICAL CHANGES OCCURRING IN OYSTERS. 
13 
Table 5. —Average values of amino-acid nitrogen and total solids of oysters washed 
by both methods. 
(Shell stock, 100 per cent.) 
Determination. 
Old 
method. 
New 
method. 
Shucker: 
Amino-acid nitrogen. 
Per cent. 
104.8 
Per cent. 
106.2 
Total solids.7. 
109.4 
107.3 
Commercial package: 
Amino-acid nitrogen. . 
95.0 
72.2 
Total solids. 
94.0 
76.0 
Considering the comparatively small number of determinations 
made, and the multiplication of error involved in expressing the 
various fractions as percentages, the figures in Table 5 are very 
satisfactory checks. They show that in the old method of washing 
the finished product contains, in a given volume, about 94 per cent 
of the food value possessed by the same oysters in the shell, whereas 
in the modern method of washing this figure falls to a percentage of 
about 74 per cent. 
This series, however, does not indicate in any way the cause of the 
loss, as the amino acids disappear at the same rate as do the total 
solids. This loss may he due almost entirely to osmosis, or it may 
be due in part to solution in the wash water of soluble parts of the 
oyster, or to both. That there is a loss of soluble matter in the wash 
water there is no doubt. This is proved by the complete disappear¬ 
ance of sodium chlorid after a comparatively short period of washing. 
Sodium chlorid and other crystalloids would wash out much faster 
than the soluble protein compounds, which are colloids, hut if the 
sodium chlorid disappears it is certain that other soluble constituents 
tend to disappear also. 
SERIES V. 
In order to determine, if possible, just what proportion of the 
apparent loss of the various constituents is due to osmotic distention 
and what proportion is due to solution in the wash water, and also 
the general chemical effect of all kinds of oyster washing, a series of 
experiments was run in which measured volumes of oysters were 
subjected to various washing processes and were both measured and 
* analyzed at various stages of washing. The results of this seiies aie 
given in Table 6, and a mathematical analysis of the results obtained 
is given in Table 7. 
Experiment 1 .—Five gallons of standards were taken from the 
chute immediately before they entered the agitation tank, carefully 
measured, put into an equal volume of water, stirred thoroughly, 
and allowed to stand. Measurements were made of both water and 
oysters every 6 hours for the first day, and every 12 hours thereafter 
for 3 days. The water was renewed after each measurement. Chem¬ 
ical determinations were made once a day upon samples taken in the 
