84 THE POPULAR SCIENCE MONTHLY. 



results of the two experiments thus computed, may be stated as 

 follows : 



In the " floating " of 100 grammes of flesh (body) of the oysters — 



The weight of— Before dialysis. After dialysis. 



Water rose from 77'9 grammes to 96'6 grammes. 



Water-free substance fell from 22-1 " " 206 " 



Whole flesh rose from 1000 " " 117-2 " 



Protein was assumed to remain the same. 106 " " 10'5 " 



Fats fell from 2-5 " " 2-3 " 



Carbohydrates, etc., fell from 69 " " 6-0 " 



Mineral salts fell from 2-2 " " 18 



Total 221 " 20-ri " 



In brief, according to these compulations, the flesh lost between 

 one sixth and one seventh of its mineral salts, one eighth of its carbo- 

 hydrates, and one twelfth of its fats, but gained enough water to make 

 up this loss and to increase its whole weight by an amount equal to 

 from one seventh to one fifth of the original weight. Assuming the 

 loss of nutritive value to be measured by the carbohydrates and fats 

 which escaped, it would amount to about one tenth of the whole. 

 That is to say, the total nutritive materials were one tenth less after 

 floating than before. 



In the liquid portion of the shell-contents, the percentage of w^ater 

 rose and that of the water-free substance fell in a very marked degree. 

 But while the w^hole percentage of water-free substance was dimin- 

 ished, that of both protein and of carbohydrates rose slightly (the 

 amount of fats was too small to be taken into account), so that the 

 falling off was all in the mineral salts. The experiments do not show 

 the exact increase or decrease in the total amounts of the liquids and 

 their constituents, so that it is impossible to say with entire certainty 

 whether there was or was not an actual gain of protein or fats or car- 

 bohydrates. It -would seem extremely probable, however, that the 

 liquids received and retained small quantities of these materials from 

 the flesh (bodies) of the animals. 



The apparent increase of protein and other miaterials belonging to 

 the body in the liquids, though slight, is very interesting. I must re- 

 fer to the detailed account of the experiments for the discussion of it 

 and of the changes in composition of the liquids. The point is that if 

 the changes in composition of the oysters in floating were due to os- 

 mose or dialysis alone, we should expect simply a gain of water and 

 loss of salts (and perhaps of soluble carbohydrates). But the flesh 

 seems to have lost a little carbohydrates and fats, and probably pro- 

 tein also, along with the salts, while it was absorbing water, the liquids 

 at the same time gaining more or less of protein and carbohydrates. 

 A way in which this may have come about is suggested by my col- 

 league, Professor Conn, who calls attention to the fact that some mol- 



