2 BULLETIN 649, U. S. DEPARTMENT OF AGRICULTURE. 



that the absorption of min eral salts is better on a diet containing 

 fresh or salt fish and poorer on a diet contai n ing dried fish than on a 

 diet containing beef. Van Slyke and White, 1 using the rate of excre- 

 tion of nitrogen in the urine as an index of the rate of protein diges- 

 tion, found that boiled cod (fresh) was more rapidly digested than 

 boiled beef, boiled weakfish. boiled mussel, and boiled cod (salt). 

 Eosenfeld, 2 in a study of the nutritive value of fish (sea pike and sea 

 salmon), concludes that fish causes the excretion of a smaller 

 amount of uric acid than meat and that fish is equal to beef for 

 maintaining nitrogen equihbrium. In digestion experiments with 

 beef and fish, Atwater 3 compared the amounts of protein, fat. and 

 ash assimilated, and obtained the same coefficients of digestibility 

 for both food materials. 



Studies of the digestibility of canned salmon have been reported 

 by Milner, 4 who found in four experiments in which an average of 

 401 grams of salmon was eaten daily for three days with a simple 

 mixed basal ration consisting of bread, milk, butter, and sugar, that 

 96 per cent of the protein and 97 per cent of the fat of the salmon 

 were retained by the body. 



A number of other investigators have studied the value of fish flesh 

 for food purposes by means of artificial digestion experiments. 

 Honigsberg 5 studied the relative digestibility of fish and found that 

 pepsin digested whitefish protein more rapidly than raw and less 

 rapidly than cooked beef. In a study of the digestibility of fish pro- 

 tein by trypsin, White and Crozier c found that boiled codfish and 

 dogfish digested more readily than boiled beef. Sulima 7 conducted 

 experiments to determine whether there were differences in food in 

 the raw state and that cooked at a high temperature which would 

 affect the digestive process and concluded that gastric digestion was 

 much slower with cooked than with uncooked fish (sardines). This 

 difference, he believed, was due to the enzyms present in the raw 

 fish. Konig and Spittgerber, 8 as a result of determinations of the 

 composition, energy value, and constants of fish fat, and a study of 

 the digestibility of fish flesh by means of artificial digestion exper- 

 iments, concluded that fish flesh is as easily and completely digested 

 as meat. 



In the earliest elaborate series of investigations of food materials 

 made in this country, Atwater 9 studied the composition of fish, 

 and the results of this investigation contributed largely to the gen- 



1 Jour. Biol. Chem., 9 (1911), No. 3-4, pp. 219-229. 



» Zentbl. Inn. Med., 27 (1906), No. 7, pp. 169-176. 



» Ztschr. Biol., 24 (1888), No. 1, pp. 16-28; abs. in Jahresber. Tier Chem., 17 (1887), p. 418. 



* Connecticut Storrs Sta. Rpt. 1905, p. 142. 



5 Wiener Med. Bl., 5 (1882), Nos. 19, pp. 582-585; 20, pp. 614-616. 



6 Jour. Amer. Cbem. Soc., 33 (1911;, No. 12, pp. 2042-2048. 



7 Arch. Hyg., 75 (1912), No. 6-7, pp. 235-264. 



8 Landw. Jahrb., 38 (1909), Sup. 4, pp. 1-169. 



s U. S. Comr. Fish and Fisheries Rpt. 1883, pp. 423-194. 



