CHEMICAL COMPOSITION OF FOOD-FISHES. 
779 
There were in all G 2 specimens of 11 species o 1 moilusks, crustaceans, 
and vertebrates. 
2 METHODS OF ANALYSIS AND ANALYTICAL DETAILS. 
METHODS OF ANALYSIS. 
The methods of analysis employed were practically those used in the 
analysis of fish, and described in a previous part of this report. A few 
notes on special details of methods used for the invertebrates, espe- 
cially the moilusks, will be in place here. 
Many of the specimens examined, as oysters, clams, etc., are liable to 
have foreign matters, mud, sea-weed, hydroids, gastropods, etc., adhering 
to their shells. These foreign materials were removed by washing, after 
which the specimens were drained and wiped dry. 
After the cleaning of their shells, the weighed oysters were opened, 
the liquid thus escaping being caught in a large evaporating dish. 
They were then put upon a porcelain colander (“ crystal drainef ”) and 
the liquid contents allowed to drain into a beaker. In this way some 
very small particles of solid matter would probably be added to the 
filtrate. For the purpose of analysis the part remaining upon the dish 
was called “flesh,” while that passing through was designated as 
“liquids.” The flesh and liquids in canned oysters and those that were 
opened before they were received were separated in the same way. 
After this separation the flesh was chopped in a wooden tray until the 
sample was quite fine, and evenly and thoroughly mixed, as was done 
with the samples of fish above reported. 
The specimens of clams and mussels were prepared in the same way 
as oysters. In the case of scallops only the part usually eaten, the 
muscle that holds the shell together (adductor muscle), was analyzed. 
This was analyzed as received, the flesh being chopped and sampled in 
the same way as that of the oyster. 
In the case of lobsters, crabs, crayfish, and turtles the flesh was 
carefully separated from the shell and prepared as above. For the 
parts taken for analysis, see description of samples in the analytical 
details which follow. 
In all of the samples a portion, usually about 100 grammes, of the 
chopped flesh was dried in hydrogen and prepared for analysis in the 
same manner as the hydrogen-dried samples of fish already described. 
The liquids were evaporated over a water bath, and then dried in air. 
After drying they were ground, sampled, and used for the determina- 
tions made in “ liquids,” the methods for which were in the main like 
that for the flesh. 
