1917] FOODS HUMAN NUTRITION. 861 



served as subjects and the fats studied were incorporated in a basal ration. 

 The results of the investigation are summarized in part as follows : 



" The fats studied in this investigation were well digested, the coefficients 

 of digestibility, with allowance for metabolic products and any undigested fat 

 supplied by the basal ration, being, for chicken fat. 96.7 per cent ; for goose fat, 

 95.2 per cent ; for brisliet fat, 97.4 per cent ; for butter fat in the form of cream, 

 96.9 per cent ; for the fat in egg yolk, 93.8 per cent ; and for the fat in fish 

 flesh, 95.2 per cent. 



"On an average, 95 gm. of chicken fat, 95 gm. of goose fat, 80 gm. of brisket 

 fat, 78 gm. of butter fat in the form of cream, 83 gm. of egg-yolk fat, and 60 

 gm. of fish fat were eaten per subject per day. In the case of goose fat, the 

 feces were noticeably soft and occasionally a more decided laxative effect was 

 noted, indicating that the limit of tolerance for this fat was not far about the 

 95 gm. which was eaten on an average. No physiological disturbance was noted 

 with the other fats tested. Such matters have a practical value in discussing 

 dietetics, aside from the theoretical question whether this laxative property is 

 ascribable to differences in the chemical structure of the fats or to some other 

 factor. 



" The average coefficient of digestibility of brisket fat is higher than that 

 previously found for beef (kidney) fat (93 per cent), which is in accordance 

 with the observation that the digestibility is inversely proportional to the 

 melting point. The other fats studied were either fluid or had a melting point 

 not far from room temperature, so it was not surprising to find that they did 

 not show marked variations in thoroughness of digestion." 



The solidity of oysters, J. Nelson {New Jersey Stas. Rpt. 1915, pp. 242- 

 246). — The solidity of oysters is defined as the proportion of the contents of an 

 oyster shell that is nutrient, as distinct from the water present. This is dis- 

 cussed in connection with the practice of floating oysters before sale, especially 

 with reference to the question of standards for determining the amount of such 

 adulteration. It is stated that three distinct practices in connection with the 

 swelling of oysters from the use of water fresher than that in which they are 

 grown must be considered. These are, first, the practice of floating oysters in 

 the shell ; second, the practice of washing shucked oysters that are marketed 

 as solid meat without liquor; and third, the practice of retailers to put the 

 open oysters into a bucket of tap water, from which they are sold after stand- 

 ing for a varying length of time. The results are reported of analyses of several 

 samples of oysters for solidity, and it is stated that each of the three cases 

 mentioned above must be studied on its own merits, and that the problem of 

 standards in any of these cases is much more complicated than in the case 

 of milk adulteration. 



The author states that there is need of further investigation of the rate and 

 amount of swelling in each of these cases, and also of the injuries and benefits 

 connected with various methods of handling oysters for sale. From the 

 standpoint of health the real menace in the practice of floating oysters lies in 

 the possibility of infection through the use of contaminated water. 



Copper content of green oysters, J. Nelson (New Jersey Stas. Rpt. 1915, pp. 

 242-249). — This article contains a rather extended discussion of the copper 

 content of oysters and the green color sometimes observed in these shellfish in 

 certain localities. It is pointed out that various samples of shellfish, which are 

 alike in showing the green color, are unlike in respect to the amount of copper 

 present. The metal may be absent from the colored substance in some cases 

 and some samples of uncolored shellfish may contain more of the metal than 

 others which are colored. There is, therefore, no reason to believe that the 

 green color is due to copper. It is further pointed out that copper is present 



