40 MISCELLANEOUS PAPERS. 



barium apparently is rendered insoluble, so that it is not extracted by 

 water, but can be extracted by digestion with the digestive ferments. 

 To be poisonous the barium must be in such a form that it can be 

 absorbed by the gastro-intestinal tract. 



(8) In deciding whether plants are poisonous it is desirable to 

 test not merely the aqueous or alcoholic extract, but also the extracts 

 obtained by digesting these plants with the ferments which occur in 

 the gastro-intestinal tract. 



(9) It is important that the ash of plants, especially of those 

 grown on uncultivated soil, as on our unirrigated plains, be examined 

 for various metals, methods similar to those by which rocks are now 

 analyzed by the United States Geological Survey being used. 



(10) It is desirable to study various obscure chronic conditions, 

 such as lathyrism, with reference to the inorganic constituents of the 

 Lathyrus and other families of plants. 



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