46 Notes from the Physiological Laboratory 



sible upon an exclusive diet of bread from white 

 flour, growth is much more active upon a diet of 

 bread containing a greater amount of inorganic 

 matter. It is possible that Liebig's estimate of the 

 needful amount of inorganic matters was too high, 

 but it is equally noteworthy that there is a ten- 

 dency on the part of late writers to give insufficient 

 prominence to the importance of these elements of 

 food. It may not be out of place here to mention 

 a striking illustration of the absolute necessity for 

 inorganic salts in the fluids of the economy, as re- 

 corded by Dr. S. Ringer. 1 This observer found 

 that while minnows were kept in ordinary tap water 

 they would live for weeks unfed. When, however, 

 they were placed in distilled water they died on an 

 average in four hours and a half. Further, that in 

 a rude imitation of spring water, made by the ad- 

 dition to distilled water of potassium and calcium 

 chlorides, and of sodium bicarbonate, the fish lived 

 on an average about two weeks. Study of the fac- 

 tors in the experiments showed that death was due 

 to a diminution of salts in the economy of the fish. 

 That such diminution, even when very slight, could 



1 Journal of Physiology, vol. iv. No. vi., Feb. 1884, in the 

 appended Proc. Physiol. Soc., session Dec. 13, 1883. 



