468 REPORT OF COMMISSIONER OF FISH AND FISHEIilES. [SGlJ 



The protein in Table II, therefore, includes all the nitrogenous com-! 

 pounds of the fish, albuminoids, gelatinoids, and so-called nitrogenous 

 extractives. 



In the preliminary report of progress of the present investigation, 

 published in the Keport of the United States Commission of Fish and 

 Fisheries for 1880, pages 243-4, 278, and 275, are given results of deter- 

 miuation of " extractives" (cold-water extract not coagulated on boil- 

 ing), albumen (cold-water extract coagulated on boiling), gelatin (hot- 

 water extract), and myosin and syntonin (insoluble protein) in a number 

 of specimens of fish. I hope in a future report to discuss these com- 

 pounds more fully, and hence only refer here to the analyses already re- 

 ported. In Table II, as in the succeeding tables of tbe composition of 

 fish, the terms protein and albuminoids, as said above, include all these 

 nitrogenous compounds of the flesh. For the sake of completeness I 

 give, with the protein thus calculated, the actual percentages of nitro- 

 gen. 



Table III. Analyses of fish (calculated on fresh substance, protein 

 by difference).— This table shows the composition of the flesh, as de- 

 duced from the figures for water and composition of water-free substance 

 in Table II. Accordingly the protein is that estimated by difference. 



Table IV. Analyses of fish (percentages of water and nutritive 

 ingredients).— This table recapitulates in more convenient form the fig- 

 ures of Table III. 



The insertion of both these tables may seem unnecessary. Table IV 

 was already in type when a change of plan, necessitated by circum- 

 stances out of the writer's control, called for the details of Table III, 

 and Table IV was allowed to stand. I think, however, it will not be 

 entirely out of place. The figures for "maximum" and " minimum '^ 

 represent the largest percentages of each of the several ingredients 

 found in the specimens analyzed. 



Table VI. Percentages of refuse, water, and nutritive ingredients 

 in specimens of fish as found in the markets.— This table gives the 

 composition of the specimens received for analysis, including both 

 flesh and refuse, and is on that account of economic importance, since 

 it shows the composition of the fish as commonly sold. The table is 

 taken from a more detailed one, which with others I have reserved for 

 a future and more extended report. 



Table VII. Composition of invertebrates, &c.— This table, deduced 

 from some more detailed tabular statements prepared for future pubh- 

 cation, recapitulates some of the more important results, from the eco- 

 nomic standpoint, of analyses of invertebrates (and two specimens of 

 vertebrate animals). In many of the shell-fish— oysters, clams, mussels— 

 the solid and liquid contents of the shells were analyzed separately. 

 The amount of nitrogen and ether extract in the liquid portion seemed 

 to me interesting, and led to more analyses of the latter than would 

 otherwise have been undertaken. In removing, the shell contents from 



