758 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 
estimation of the protein. The fact that the majority of the determina- 
tions of these substances were made not in duplicate but singly would, 
unless unusual care was exercised in the work, leave grounds for fear 
that errors might have entered into them. That Almen was himself 
persuaded that his determinations might not have been free from mis- 
takes, he takes pains to state in his references to the differences which 
occur between the amounts of protein as estimated by the two methods. 
Thus, the quite wide differences between the two estimations in the 
fresh mackerel (1.6 per cent.) and in the perch (0.9 per cent.) he attributes 
to probable errors in the nitrogen determination. While I would wish 
to refrain from criticism of the labor of a fellow-investigator, it is not 
easy to avoid the feeling that greater care in the analytical work would 
have yielded less uncertain results. At the same time, my own analy- 
ses,* already given, show variations between the amounts of protein as 
directly determined (albuminoids by difference of the tables) and the 
amounts obtained by multiplying the nitrogen by 6.25 as large as, or 
nearly as large as, those here stated, though of course in my own anal- 
yses the protein refers to the whole nitrogenous material, while in this 
case Almen includes only the true protein compounds, the albuminoids 
and the geiatiuoids, the extractive matters being excluded. 
SOLUBLE AND INSOLUBLE SALTS, CHLORINE, ETC. 
Some of Almen’s other conclusions are of decided interest. The 
insoluble salts he regards as including, in some cases, the phosphates 
of the small bones which are not separated from the flesh. The soluble 
salts vary between 0.5 per cent, and 1.5 per cent, in the flesh. The 
smallest portion was in the lean beef ; the percentage in the different 
kinds of flesh of fishes being considerably larger. 
The amount of chlorine is very insignificant. No difference is observ- 
able, either between the chlorine in the fresh-water and sea-water fishes 
or between the flesh of fishes and lean beef; but, as Almen observes, it 
is to be remembered that the chlorine was determined in the ash, from 
which a portion may have escaped in the ignition. 
STATEMENTS REGARDING INDIVIDUAL SPECIMENS. 
As stated above, in the descriptions of the methods of analysis, Alm6n 
analyzed the flesh and skin of the fish together, regarding these as 
constituting the edible portion and the remainder as refuse. Reference 
to the details of his memoir, however, shows that in some cases the 
flesh alone was used, the skin being rejected. The following statements 
in Almen’s description of the individual specimens are also worthy of 
especial record : 
No. xxx. The first specimen in the table was, 1 ‘An ordinary fresh- water eel weighing 
328 grammes. The skin was removed and weighed 35 grammes or 11 per cent, of the 
whole. The flesh freed from bones and other refuse weighed 209 grammes, or 64 per 
cent, of the whole eel. The head and other parts not used for food amounted to 36 
per cent.” In this very fat fish, therefore, the refuse, as Alm6n remarks, made up a 
* See Section A, Divisions 4 (Tables 2 and 3) and 5, above. 
