THE ASH OF PLANTS. 173 
In the older analyses of other classes of agricultural 
plants, especially in root crops, similarly great variations 
occur, 
Some uncertainty exists as to these older data, for the 
reason that the estimation of soda by the processes custom- 
arily employed is liable to great inaccuracy, especially 
with the inexperienced analyst. On the one hand, it is 
not easy, (or has not been easy until lately,) to detect, 
much less to estimate, minute traces of soda, when mixed 
with much potash; while on the other hand, soda, if pres- 
ent to the extent of a per cent or more, is very liable to 
be estimated too high. It has therefore been doubted if 
these high percentages in the ash of grains are correct. 
Again, furthermore, the processes formerly employed for 
preparing the ash of plants for analysis were such as, by 
too elevated and prolonged heating, might easily occasion 
a partial or total expulsion of soda from a material which 
properly should contain it, and we may hence be in doubt 
whether the older analyses, in which soda is not mention- 
ed, are to be altogether depended upon, 
The later analyses, especially those by Bibra, Zoeller, 
Arendt, Bretschneider, Ritthausen, and others, who have 
employed well-selected and carefully-cleaned materials for 
their investigations, and who have been aware of all the 
various sources of error incident to such analyses, must 
therefore be appealed to in this discussion. From these 
recent analyses we are led to precisely the same conclusions 
as were warranted by the older investigations. Here fol- 
lows a statement of the range of percentages of soda in the 
ash of several field crops, according to the newest analyses : 
Ash of Wheat kernel, none, Bibra,. to 5%, Bibra, 
wo up Cameron, ‘c 0 
otato tuber, none; ) Metzdorff, 4|, Wolff, 
Bibra, 
«6 5 § 1%o Bibra, « 8g i 
Barley kernel ‘ dol? Zoeller, + | yolanaan, 
4.7|, Ritthausen, ‘* 29. Bo1° Ritthausen, 
“ Sugar beet, 5.%|, Bretschneider 16.6}, Bretschneider. 
“6 “ Turnip root, %.7|, Anderson, ‘ 17.15], Anderson. 
