~— 
702 WHEAT. 
{ 
. Ash Chlor. 
: : : ep Phos uth Carb. |; ; Mag- |Perox.| Pot- 
ae Varisty- Soil. per | Silica. | “a cig. | Acid. | Acid. Lime. | nesia. Tron. | ash, | ®°4| of 
. cent. Sod. 
2 | Hopeton, Stonebrash, . 1:81 | 2:84 | 47:00} 0:24 | 0:23 | 820 /}12°71] 060] 33:15] ... 600 
10 Ditto, Calcareous brash &clay| 1°51 | 1°41 | 4618, 048] ... 2°82 | 13:99] 0°00 | 83:00} 2:07] ... 
| 11 | Spalding, Calcareous, 181 | 2:23 | 48:21] O11 } 0:22 | 288 | 11:06] 0:23 | 29°76} 5:26] ... 
; 12 | Hopeton, i 1:48 | 5:91 | 41:22] 1:91 | ... | 4:29 | 13-57] 1:36 | 27:06} 4:08 | 0°55 
| 26 | Creeping wheat, | Clay and sand, 1:73 | 5:32 | 4649] O61) ... 150 | 12°35 | 0°22 | 3118} 242) ... 
27 Ditto, Ditto, . 165 | 2°55 | 45°64] 155] ... 6°76 | 13°06 | O-11 | 28°89} 1:40 is 
28 Ditto, Calcareous rubble, 1:71 | 1°34 | 48°53) ... Bic 3°72 | 12°74} 1:40 ' 30°94} 1:28 Bes 
29 | Red-straw white,| Loam (green-sand), 1:70 | 9:71 | 4091} 0°08 | 016 | 1°45 | 9:53} 3:34 | 31:00} 2°54 | 0:34 
3 Hopeton, Loam, . A 1:56 | 2:28 | 45:73 | 0°32] ... 2:06 | 10:94 | 2-94 | 32°24) 4:06 | 0:27 
31 | Hopeton, . Flint and chalk, 1°63 | 4:43 | 45°30} 059] ... 183 | 12°43 | 1°76 | 29:92} 6:08 | 064 
384 | French wheat, c 155 | 38:05 | 43°47] 0°35 3°47 | 13°94 | 0:97 | 8239) 2°32] ... 
35 | Egyptian wheat, . 1:97 | 4:97 | 4103] 018 4:34 | 1112] 118 | 36:60] 053] ... 
386 | Odessa, 0 C 1:50 | 448 | 45°80) ... 317 | 14:28; 0°89 | 80°30] 1:00] ... 
37 | Marianople, . . : 1:70 | 4:00 | 34-44] 0:24 2°05 | 14:09 | trace | 85°77 | 9:06 0 
38 | Hopeton, Silicious sand, 161 | 4:23 | 39:97} O15 132 |13:26] ... | 38643] 462 
39 Ditto, Stiff clay, 163 | 3:05 | 47°33] ... 4:43 | 9°32] 0°35 | 32:05] 3:38] . 
40 Ditto, Sandy, . 6 1-71 | 5°63 | 43:98} 0:21 1:80 | 11:69 | 0:29 | 34°51) 187] ... 
41 Ditto, . Clay, é * 169 | 3°69 | 49:22] 0-18 2°51 | 12°38} 0-08 | 30°32 | 0:07 | 1:60 
42 Ditto, Silicious sand, 1:76 | 3:29 | 44-44) ... 8-21 | 967)| 0°08 | 38214] 214] ... 
43 | Red-straw white,} Silicious sandy loam, 1°72 | .2:14 | 49°58] 060) ... 3°27 | 18°75 | 0°23 | 29°75} 0°64 
44 Ditto, . Ditto, 1-73. | 2°63 | 47-44) ... foc 3°39 | 14:05 | 0°67 | 29:91] 1:87 
45 Ditto, . Calcareous (carbonif), | 1°61 } 2°76 | 47°38} 0°07] ... 6°87 | 11°46 | 0°07 | 8013] 1:25 
46 Ditto, . ree loam, . Aa 160 | 3:89 | 46:79] ... 1:15 | 13°39! 0:91 | 30°02] 3°82 
; aleareous and sili- } : ; : i 1a ; ; ; 
47 Ditto, . { cious sand and clay 1:90 | 217 | 4661} 044] ... 5°05 | 14:22} 0:09 | 2917 | 2-20 
48 Ditto, . | Magnesian clay, 1:73 | 2:05 | 46°99} 0:24] ... 678 | 12:76 | 2°32 | 26°70 | 2°12 
50 | White wheat, Chalk, . 5 1:84 | 5:46 | 40°57] 032] ... 3°21 | 956] 2:06 | 34:26 | 4:53 
It will be seen that the first named, silica, consti- 
tutes only a very small proportion of the whole ash; 
it probably exists only in the skin as a mechanical 
protection to the grain; in quantity it varies between 
the limits of 1°30 and 6:00 per cent. ; in one instance 
however the ash contains as much as 9:7] per cent. 
of this substance, Spec. 29. The specimen in which 
this unusually large quantity of silica occurs, is also 
remarkable for the very large proportion of oxide of 
iron present in its ash; it was grown on the ‘ green- 
sand,’ and hence in all probability the peculiarity re- 
ferred to. ‘The green-sand owes its colour to the 
large quantity of silicate of protoxide of iron existing 
init. When decomposed by liming, or water con- 
taining carbonic acid, it would furnish an abundant 
supply of both these substances, which would pass 
into the plant. The average proportion of silica in 
the ash of wheat upon the 28 specimens in the table 
is 3°66 per cent. Phosphoric aeid, the next body in 
the table, is certainly the most important of all the 
mineral ingredients of wheat, both on account of the 
large proportion of it which exists in the ash, and the 
very small extent to which it is present in soils. The 
ash of wheat contains a quantity of this substance, 
varying between 40 and 50 per cent. of its weight. 
In one specimen however (No. 37) the phosphoric 
acid does not exceed 35 per cent.; but this result 
does not accord with any other we have obtained. 
The specimen alluded to is from Marianople; it is in 
peculiarly small and thin grains, almost approaching 
in appearance those of rye; it is of interest also in 
containing a large proportion of soda, not in the place 
of potash, but in addition to the usual amount of the 
latter alkali. Specimens 41 and 43 exhibit the high- 
est amount of phosphoric acid in any of the ashes. 
The mean of phosphoric acid in all the specimens is 
45°00 per cent. of the ash. A bushel of wheat of 61 
lbs., containing 1°67 per cent. of mineral matter, 
would require 7,3; oz., or taking 28 bushels an acre 
as an average, we should remove from the soil in the 
grain of every acre of wheat 12 ]bs.3 0z. The larg- 
est amount removed in any crop examined is seen in 
specimen 47, where it reaches 22 lbs. 50z. This 
sample has been before noticed, from the large amount 
of ash taken off in the straw; it is In all respects an 
extreme case, the ash of the grain, the straw, and the 
chaff, being all unusually high. The large amount 
of crop with these high percentages renders the spe- 
cimen the most exhausting of all those which have 
fallen under our notice. Sulphuric acid is generally 
present in the ash of wheat, though in small propor- 
tion; it does not exceed in any instance 2:00 per 
cent., and is usually much less than this. The mean 
quantity of this acid in the ash is 0°34 per cent., and 
the largest amount removed by an acre of wheat (in 
this grain) 8 oz. Carbonic acid is an ingredient of 
many ashes; but in the grain of wheat it is seldom 
met with. The presence of carbonic acid in an ash 
indicates the existence of organic acids combined 
with lime, &c., in the plant. The grain of wheat, 
however, would appear in its matured state never to 
possess any such organic salts; and consequently the 
column appropriated for this acid in the table is al- 
most void. Lime is another ingredient in the ash of 
wheat: in quantity it varies between 1-5 and 8:00 per 
cent., being more frequently near the former than the 
latter number. The mean quantity is 3°61. The 
largest amount removed from an acre is seen in Spec. 
42, where it is 3lbs.9 0z. Magnesia is a highly im- 
portant constituent of plant ashes: in wheat it varies 
between 9:00 and 14:00 per cent. of the ash—more 
often however being found to constitute 11 or 12 per 
cent. of the mineral matter. Our analyses give us 
as a mean 12°36 per cent. A bushel of 61 Ibs. con- 
tains 2 oz., and an acre of 28 bushels will remove 3 
Ibs. 8 oz. The largest quantity of magnesia remov- 
ed in any crop examined by us was 6 lbs. 13 oz. 
(Spec. 47). Peroxide of iron exists to a small ex- 
tent in the ash of wheat: its quantity varies between 
0°25 and 3°5, the smaller number being nearer the 
ordinary quantity. It is remarkable that those spe- 
cimens which contain most iron are from the chalk 
districts, or analogous soils. ‘The average propor- 
tion of peroxide of iron is 0°81, and the largest 
amount removed from an acre (Spec. 29) | lb. 6 oz. 
Potash is, next to phosphoric acid, the most consid- 
erable and important of all the substances which exist 
in wheat ash: in quantity it varies between 27 and 
37 per cent., having about the same latitude as phos- 
phoric acid. The mean of 26 specimens is 31°37. A 
bushel of wheat (61 lbs.) will contain 5 oz., and an 
acre of 28 bushels will carry off 8 lbs. 15 0z. The 
largest quantity described in the Report as removed 
from an acre is 14 lbs. Soda is an alkali scarcely 
ever entirely absent from wheat, but present only in 
small quantity. When compared with potash, it va- 
ries between 1 and 5 per cent. of the ash. In one 
instance, that of the Marianople wheat before men- 
tioned, its quantity is comparatively large, reaching 
9 per cent.; but we have as yet met with nothing to 
induce us to adopt the opinion of Liebig, of the sub- 
stitution of one alkali for another. At all events 
