THE CHEMISTRY OF " OYSTER-FATTENING:' 83 



haps be permissible to cite a few of the statistics. I give more de- 

 tails than would perhaps be appropriate in these pages, were it not 

 for the novelty of the results, and the importance of their bearing 

 upon the physiology of absorption of nutritive material in our bodies 

 as well as upon the nutritive value of the oysters. 



The changes in the constituents of the body ("flesh") were mainly 

 such as would be caused by osmose, though there were indications of 

 secretion of nitrogenous matters and, especially, of fats, which are not 

 so easily explained by osmose. This I will speak of later. 



The amounts of gain and loss of constituents which the bodies of 

 the oysters experienced may be estimated either by comparing the per- 

 centages found by analysis before and after dialysis, or by comparing 

 the absolute weight of a given quantity of flesh and the weights of 

 each of its ingredients before, with the weights of the same flesh and 

 of its ingredients after, dialysis. For the estimate by the first method 

 we have simply to compare the results of the analyses of the floated 

 and the not-floated specimens. Taking the averages of the two ex- 

 periments, it appears that — 



The percentages of— Before dialysis. After dialysis 



Water rose from 779 to 82'4 



Water-free substance icll i'rom 22-1 " 17'G 



Total flesh 100-0 IGO-Q 



Protein fell from 10-5 to 8-9 



Fat fell from 2-5 " 1-9 



Carbohydrates, etc., fell from G*9 " 5'2 



Mineral salts fell from 22 " I'S 



Total water-free substance in flesh 22'1 17'6 



There was, accordingly, a gain in the percentage of water and a 

 loss in that of each of the ingredients of the water-free substance. 

 This accords exactly with the supposition that during the floating the 

 flesh gained water and lost salts and other ingredients. 



It will be more to the point to note the absolute increase and de- 

 crease in amounts of flesh and its constituents — in other words, the ab- 

 solute gain or loss of each in the floating. Estimates by this method 

 have been made and explained in the detailed accounts referred to. 

 They make it appear that 100 grammes of the flesh as it came from 

 the salt water was increased by floating, in one specimen, to 120-9, and 

 in the other to 113-4 grammes. This is equivalent to saying that the 

 two specimens of flesh gained in the floating, respectively, 209 and 

 13-4 per cent, or, on the average, 1T"3 per cent of their original weight. 

 By the same estimates the water-free substance in the 100 grammes of 

 flesh before the floating weighed, on the average, 22*1 grammes, while 

 that of the same flesh after floating weighed only 20*6 grammes, 

 making a loss of 1*5 gramme or 6-6 per cent of the 22*1 grammes 

 which the water-free substance weighed before dialysis. The main 



