CHEMICAL COMPOSITION OF FOOD-FISHES. 
793 
3. ANALYSES OF AMERICAN MOLLUSKS, CRUSTACEANS, ETC. 
DESCRIPTION OF THE TABLES. 
Table 33 contains a list of the specimens analyzed. The specimens 
of oysters, and of other species as well, are arranged in order of the 
locality from which the specimens were obtained, the more northern 
coming first. In the second column is given the date of receipt of the 
samples at the laboratory. In most cases they had been taken from the 
water two or three days before being received by us. As will be seen in 
the third column, the number taken for analysis was generally large in 
order to obtain a fair sample. In the fourth column are given the total 
weights of the samples taken for analysis, and in the fifth the average 
weights of the individual specimens. Details as to the proportions of 
shell, flesh, liquids, total edible portion, etc., in the several samples of 
oysters and other invertebrates, are given under the heading “ Constit- 
uents in whole specimen.” The figures for “ flesh ” denote the per- 
centage of solids or “ meat f those under liquids, the liquid portion, 
“ liquor” iu the sample. The solids and liquids together are designated 
“total edible portion,” which with refuse and loss in preparation make 
up the whole sample. 
Under the heading “ In flesh ” are given the percentages of water and 
dry substance iu the flesh. After these follow the same percentages 
for liquids and for the total edible portion. 
Table 34 gives the proximate percentage composition calculated on 
water free (dry) substance. The percentages of albuminoids were 
obtained by multiplying the percentages of nitrogen by the factor 6.25. 
Table 35 contains the results of the analyses calculated to the water 
content of the fresh substance. The term, “ fresh substance,” as here 
used, refers to the flesh and liquids as they were obtained by the sepa- 
rations described under methods of analysis of invertebrates, etc. The 
percentages in the column headed “ Extractives” are obtained by dif- 
ference. That is, the albuminoids (as computed by multiplying nitro- 
gen by 6.25), fats, and ash, are added and their sum subtracted from the 
total dry substance. Though this method of computation is common in 
the statements of the composition of animal and vegetable materials, it 
is, of course, only an approximately accurate way of getting over the 
difficulty of determining and stating the amounts of the several ingre- 
dients. It will be noticed that u extractives ” as thus determined by 
difference are not the same as the “ extractive matters ” of the tables of 
the fish analyses. 
Table 36 gives the percentages of phosphorus, calculated as phospho- 
ric anhydride, and of sulphur calculated as sulphuric anhydride. The 
percentages are given calculated to dry substance and to fresh substance. 
