THE ROLE OF SOME INORGANIC ELEMENTS IN NUTRITION. 
By LAFAYETTE B. MENDEL anp THOMAS B. OSBORNE. 
(From the Laboratory of the Connecticut Agricultural Experiment Station 
and the Sheffield Laboratory of Physiological Chemistry in Yale 
University, New Haven.) 
- The relative importance of the individual inorganic salts was 
long ago determined for plants, but hitherto no such definite 
knowledge of the requirements of animals has been possible owing 
_ to the failure of animals to thrive on a diet of purified foodstuffs. 
Now that the essential factors of a successful dietary have been 
ascertained it has become possible to prepare rations in which 
the individual ions are excluded except for the unavoidable small 
amounts present in the products used to supply the water-soluble 
vitamine or found as impurities in the other ingredients of the 
food. 
From experiments with such diets it has been demonstrated 
that calcium and phosphorus are needed in considerable amounts; 
for with only a trace of either of these elements in the food, rats 
failed to grow and sooner or later declined. On diets in which 
only supposedly insignificant quantities of magnesium, sodium, 
potassium, or chlorine were present growth at a normal or nearly 
normal rate was made for about 1 year. Where both sodium and 
potassium were present in the above small amounts no growth 
occurred. 
THE NUTRITIVE PROPERTIES OF KAFIR. 
By ALBERT G. HOGAN. 
(From the Department of Chemistry, Kansas Agricultural Experiment 
Station, Manhattan.) 
Our investigations of the nutritive properties of kafir were in- 
terrupted, and as some time may elapse before this study can be 
resumed we deem it advisable to take this opportunity of mak- 
ing a preliminary report. Although we have a high degree of 
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