THE ASH OF PLANTS. 171 



The composition of the ash of a number of ordinary 

 crops is concisely exhibited in the subjoined general state- 

 ment. 



May- L . Phosphor- sai , a Sulphur- rj .i nrine 



Alkalies, nesia. L * me - i c Acid. lca " ic Acid. ^ nlorine ' 



CEREALS 



Grain*.... 30 12 3 46 2 2.5 1 



Straw... 1327 37 5 5070 2.5 2 



LEG u: MK s 



Kernel... 44 7 5 35 14 2 



SI raw... 2741 7 2539 8 5 26 67 



ROOT CROPS 



Roots.... 60 39 612 818 1-4 512 39 



Tops.... 37 3 16 10 35 38 3 613 517 



<;J;.\SSES 



In flower.. 33 4 8 8 35 4 5 



3. Different parts of any plant usually exhibit decided 

 differences in the composition of their ash. This fact is 

 made evident by a comparison of the figures of the table 

 above, and is more fully illustrated by the following anal- 

 yses of the parts of the mature oat-plant, by Arendt, 1 to 

 6 (Die Haferpflanze, p. 107), and Norton, 7 to 9 (Am. 

 Jour. ScL, 2 Ser. 3, 318). 



The results of Arendt and Norton are not in all respects strictly com- 

 parable, having been obtained by different methods, but serve well to 

 establish the fact in question. 



We see from the above figures that the ash of the lower 

 stem consists chiefly of potash (81 % ) This alkali is pre- 

 dominant throughout the stem, but in the upper parts, 

 where the stem is not covered by the leaf sheaths, silica 

 and lime occur in large quantity. In the ash of the leaves, 

 silica, potash, and lime are the principal ingredients. In 

 the chaff and husk, silica constitutes three-fourths of the 

 ash, while in the grain, phosphoric acid appears as the char- 



*Exclusive of husk. 



