CHEMICAL CHANGES' OCCURRING IN OYSTERS. 
23 
stock but with air agitation, it is seen that they are in very close agree¬ 
ment throughout. This shows that the air has little or no effect as 
such, its effect being only to keep the oysters in motion, so that 
osmosis will attain a maximum value. The results of Experiments 
9—A, 10-A, 11, 12; and 15 all agree fairly well, though differences in 
stock and in methods of handling cause rather large discrepancies in 
some cases. 
SUMMARY. 
1. The determination of ammoniacal nitrogen by the Folin method 
is of very little value in estimating the amount of decomposition which 
has occurred in oysters during preparation for the market, because of 
the repeated washings to which they are subjected. 
2. For the same reason the determination of amino-acid nitrogen 
also is useless in estimating decomposition in oysters undergoing 
commercial treatment, although it is a reliable index of the amount 
of washing or soaking which the oysters have received. 
3. A marked loss of oyster solids and of ash constituents occurs on 
washing oysters with fresh water. 
4. Oysters covered with water, hut not agitated, are not appreciably 
affected by osmosis, except in relatively long periods of time. Solu¬ 
tion proceeds slowly, but amounts to a large percentage of the solids 
originally present in the course of two or three days. 
5. If oysters are agitated in fresh water, either by mechanical means 
or by means of a blast of air, a large increase in volume results in a 
short space of time, amounting to as much as 35 per cent in 30 min¬ 
utes, and to as much as 50 per cent in 90 minutes in these experiments. 
This increase is believed to be due to osmotic action. As many 
shucked oysters prepared for the market are washed by this method 
and sold by measure, it follows that the consumer may be buying 
added water. 
6. When oysters were washed in unpolluted water of approximately 
the same salinity as that in which they were grown, no increase in 
volume was found to occur, the actual loss of nutrients was slight, 
and the oysters were cleaned as effectually as they were by being 
washed in fresh water. 
7. The old method of washing oysters on a skimmer with a hose 
and paddle gives much less osmotic loss, and, therefore, a much higher 
content of total solids than does the method of washing by a water 
current and air agitation. 
8. The amount of osmotic distention of which oysters are capable 
has not been determined. It is at least 50 per cent of the original 
volume in the oysters under experimentation. 
9. These experiments seem to indicate that there is no connection 
between soaking and “bleeding' ; in the commercial package (that is, 
