[25] CHEMICAL COMPOSITION AND VALUE OF FISH FOR Foop. 255 
“Preparation of Sample” above. The percentages in the column headed 
“extractives” are obtained by difference. That is, the albuminoids (as 
computed by multiplying nitrogen 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 statements of the composition of animal 
and vegetable foods it is of course only a convenient and approximately 
accurate way of getting over the difficulty of determining and stating 
exactly the amounts of the several ingredients. It will be noticed that 
“extractives” as thus determined by difference are not the same as the 
“extractive matters” of the tables of analyses of fish. 
The most important column from an economic point of view is the 
one headed “nutritive valuation.” The calculations are based upon the 
standards assumed by Konig, and explained by Professor Atwater. 
Their valuations, though not absolute, are doubtless sufficiently accurate 
for purposes of comparison. 
PREVIOUS ANALYSES OF INVERTEBRATES. 
But very little work has been done hitherto in the way of analyses of 
invertebrates. In the very full compilation of analyses of this sort, given 
by Konig (Nahrungsmittel I. 17), one of a sample of oyster and one of 
the salt flesh (salted in brine) of a crustacean (‘‘Arebsfleisch, eingemacht”) 
are recorded, both analyses being by Konig and Kraut. The analy- 
ses are given below. Mr. R. H. Chittenden has reported analyses of 
two samples of American scallops (Pecten irradians) with results as ap- 
pended, except that in the figures herewith the percentages of albumin- 
oids have been, for reasons above stated (see Methods of Analysis), reeal- 
culated by multiplying the nitrogen by 6.25 instead of 6.4, the factor 
employed, perhaps more justly, by Mr. Chittenden. The extractives 
are estimated by difference, as explained above. 
Water. |Albuminoids.| Fats. Extractives. Ash. 
Per cent.| Per cent. Per cent.| Per cent. Per cent. 
Oysters HULOpeali eta ics -cicwreie sore ewes <eymierare 89.69 4.95 0.37 2.62 2.37 
= Ker ebsflesch,” HUrOpeaNn - ..-<s0ccccss cent 72.74 13.63 0.36 0.21 13.06f 
Scallop; American ..... sscscccsccscstrsececs 79.63 15.31 0.31 3.49 1.26 
Scallop, fAMerican 2. .'. scosdec cee. woe 80.25 14.69 0.28 3.55 1.23 
* The analysis of the oyster included the total shell contents. 
t Of the ash of the Krebsfleisch”’ 11.98 per cent. was sodium chloride. 
PART ILT. 
GENERAL SUMMARY OF RESULTS OF ANALYSES OF FISH 
AND INVERTEBRATES. 
The object of the present investigation has been to obtain informa- 
tion as to both the chemical constitution of the flesh of the animals in- 
vestigated and their economic values especially for food. 
The work thus far accomplished must be regarded as barely a begin- 
