504 CHARLES A. DAVIS 



which, on being separated and tested, proved to be calcium 

 oxalate. It was evident that the calcium salt in the plant was 

 stable and readily soluble in water. This latter fact was farther 

 demonstrated by evaporating some of the extract to dryness 

 and again taking it up with water. Almost the entire amount 

 of the calcium salt was redissolved, only a small portion of it 

 becoming insoluble and precipitating as the carbonate. This 

 ready solubility demonstrated the fact that the salt was not 

 derived from the incrustation on portions of the plant used, and 

 the same fact excluded from the list of possible compounds, 

 salts of some of the mere common organic acids found in plant 

 juices, which are insoluble. 



Qualitative chemical tests were, however, made to determine, 

 if possible, whether any of these acids were present with nega- 

 tive results, and it was demonstrated by this means that there 

 was but a single salt present and not a mixture. Search was 

 then made to determine the acid present, and a result obtained 

 which was so unexpected that it was seriously questioned and 

 the work was gone over again. The second result confirmed the 

 the first and the work of ascertaining the correctness of these 

 two results was turned over to Mr. F. E. West, Instructor in 

 Chemistry in Alma College, who had had special training and 

 much practice in organic analysis. His work was done entirely 

 independently, with material gathered at a different season, and 

 by another method of analysis, but his results were identical 

 with my own, and show that calcium exists in the water extract 

 of Chara as calcium succinate. The fact that the succinate is 

 one of the few water soluble calcium salts and that there is a 

 soluble salt of the metal in the cell sap of the plant makes it 

 probable that this is the compound of the metal which the plant 

 accumulates in its cells. 



It is not possible from actual investigation to explain the 

 method by which the calcium salt is abstracted from the water, 

 where it exists as the acid- or bi-carbonate or the sulphate^ in 



' It has been shown that Chara decomposes several calcium salts, the sulphate 

 among others. 



