THE ASH OF PLANTS. 181 



first charred at a heat of low redness, and then leached 

 with water, which dissolves the chlorides, and separates 

 them from the unburned carbon and other matters, chlo- 

 rine is invariably mentioned. In the tables of analyses, 

 the averages of chlorine are undeniably too low. This is 

 especially true of the grains. 



The average of chlorine in the 26 analyses of wheat by 

 "Way & Ogston, p. 150, is but 0.08° 1^,, it not being found at all 

 in the ash of 21 samples. In Zoeller's later analyses, chlorine 

 is found in every instance, and averages 0.7° |„. Weber's 

 analysis, as compared with the others, would indicate a 

 considerable range of variability. Weber extracted the 

 charred ash with water, and found 6° |„ of chlorine, which 

 is six times as much as is given in any other recorded anal- 

 ysis of the wheat kernel. This result is in all probability 

 erroneous. 



Like soda, chlorine is particularly abundant in the stems 

 and leaves of those kinds of vegetation which grow in soils 

 or other media containing much common salt. It accom- 

 panies soda in strand and marine plants, and, in general, 

 the content of chlorine of any plant may be largely in- 

 creased or diminished by supplying it to, or withholding 

 it from the roots. 



As to the itidispensableness of chlorine, we have some- 

 what conflicting data. Salm-Horstmar concludes that a 

 trace of it is needful to the wheat plant, though many of 

 his experiments in reference to the importance of this ele- 

 ment he himself regards as unsatisfactory. Nobbe & 

 Siegert, who have made an elaborate investigation on the 

 nutritive relations of chlorine to buckwheat, were led to 

 conclude that while the stems and foliage of this plant are 

 able to attain a considerable development in the absence 

 of chlorine, (the minute amount in the seed itself excepted,) 

 presence of chlorine is essential to the perfection of the 

 kernel. 



On the other hand, Knop excludes chlorine from the 



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