WHEAT. 
in quantity, or if (as we believe) its quantity does 
not fall far short of average years, that the proportion 
of straw to grain is usually very much overstated. 
‘¢The quantity of chaff in wheat does not, as far 
as we can discover, depend upon the amount of 
straw, but bears a general though perceptible rela- 
tion to the grain. To the latter it stands in the pro- 
portion of 1 to 5} on an average of 1 cewt. of chaff to 
every 10 bushels of wheat. Both straw and chaff 
are found in some cases to present singular deviations 
from the usually observed proportions: this is pecu- 
liarly the case in Piper’s thickset wheat, Spec. 32, 
where the straw does not much exceed the half of 
the weight of the grain—the chaff, however, remain- 
ing constant. We do not observe that the soil has 
exercised much influence on the quantities of straw 
and chaff—the average of clays, of sandy and calca- 
reous soils, being in our experiments very similar. 
‘* We desire now to point out the connexion which 
exists between the specific gravity of the grain and 
the value of different specimens of wheat. The spe- 
cific gravity of wheat is its true weight, with which 
no peculiarity of shape or size of the grains, no damp- 
ness or roughness of the skin, can interfere. Every 
farmer knows that the weight per bushel is most 
materially influenced by these circumstances, and, 
making allowances for them, is accustomed to con- 
sider it as asure criterion of the value of the sample. 
It is known that the strength of flour and its fitness 
for making good bread is due to the gluten contained 
in it, and corresponds toa considerable extent with 
the weight per bushel—the greater the weight per 
bushel the better the flour; but setting aside the 
accidental differences of skin which are the result of 
thrashing in damp weather, &c., and taking two 
wheats as nearly alike as possible in this respect, the 
question to decide will be—Is the wheat of most 
pounds to the bushel necessarily the heavier ?—in 
other words, Does it contain more gluten? Is it the 
best for the baker, the most nutritive for the con- 
sumer? We are prepared to show that it is not. 
The subject of specific gravity is rather difficult for 
parties unaccustomed to these matters to conceive, 
and it is particularly so in the case of a body con- 
sisting of individual grains like wheat. It is easy to 
understand and express the relation in weight exist- 
ing between a cubic foot of water, of marble, and of 
iron. We should find, if we weighed this quantity 
of the three substances named, that the marble would 
weigh nearly three times and the iron seven times as 
much as the water. But the weight of a given bulk 
of any substance can only be compared with that of 
another (for the sake of determining the relative 
weights of the matter composing them) when there 
are no interstices or hollows in it. Wood is consid- 
ered to be lighter than water because it floats upon 
it, but this is due to the air contained in its pores. 
Wood is really much heavier than water, and in con- 
sequence sawdust will be found very shortly to fall 
to the bottom of a vessel of water into which it 
is thrown. Now this reasoning applies equally to 
wheat. Were the grains of wheat solid bodies of 
large dimensions, so that they could readily be mea- 
sured by the rule, or indeed were the grains all ex- 
actly of one size, the relative weight of two speci- 
mens could easily be made out; but this is not the 
case. A bushel of wheat is in the same predicament 
as a mass of wood; we cannot tell the true weight 
of the matter composing one or the other by weigh- 
ing a certain measure of it, because the interstices 
between the grains of two specimens of wheat may 
differ in the same way as the pores or hollows of two 
kinds of wood. The weight, then, of any measure 
of two different grains will not correspond with their 
relative weight, supposing them solid, and therefore 
the weight per bushel may differ, the real weight 
remaining the same, or vice versa. ‘This will be bet- 
699 
ter seen if we collect in a table the specific gravities 
and the weights per bushel of those specimens which 
we have examined. . 
5} 
, on 23 4 
No. Variety. Soil. El Stag 
5 - SS as 
28 2 283 
ai <{ 
lbs 
1 Hopeton, Stonebrash and clay, 1374 60 1-76 
2 Ditto, Stonebrash, 1342 59 1:81 
3 April wheat, . Ditto, : - 41387 61 179 
4 Spring wheat, Calcareous clay, 1376 58 1-74 
5 Bristol red, 5 Brash and clay, . 1°70 612 1:54 
6 Clover’s red, Stonebrash, 1383 613 1°55 
7 Red-chaff Dantzic, Brash and clay, 1387 = 61 1:36 
8 Piper’s thickset, Ditto, A 1350 =61 1-48 
9 White-chaff wheat, Ditto, e 1313 59 1:54 
10 Hopeton, Ditto, : 1354 =61 L151 
11 Spalding, . Stonebrash, 3) UBdiy | Gil 181 
13 Creeping wheat, Clay and grit, 1375 = 62 1:55 
14 Spring wheat, Sand, clay, and grit, 1370 62 159 
15 White wheat, . Clay and grit, 1368 60 1°68 
16 Spring wheat, Calcareous loam, 1373 62 169 
17 Creeping wheat, Ditto, 1394 62 172 
18 Ditto, Hazel loam, 1387. = 61 1:90 
19 Ditto, . 4 Heavy tough clay, 1376 62 150 
20 Spring wheat, Tough clay, 1363 62 1°60 
21 Hammond’s wheat, Free clay loam, 1354 60 1:94 
22 Red Britannia, Strong clay, 1369 62 1°82 
25 Red wheat, Weak clay loam, 1°352 = 60 175 
24 White wheat, . Weak sandy clay, 1351 = «61 1:59 
25 Creeping wheat, Red clay, A 1367 613 1:70 
26 Ditto, : Clay and sand, 1365 62 1:73 
27 Ditto, Q Ditto, 2 1372 622 1°65 
28 Ditto, Calcareous rubble, 1394 863 171 
29 Red-straw white, Six inches good loam, 1°385 61 1-70 
30 Hopeton, Three inches loam, 1:412 60 1:56 
31 Ditto, : Flint and chalk, 1°356 56 1:63 
32 Piper’s thickset, Good loam, 1339 59 1-73 
33 White wheat, Alluvial, I 1382 60 1:60 
38 Hopeton, Gritty silicious sand, 1°403 63 161 
39 Ditto, 6 Stiff clay, . 1382 613 1°63 
40 Ditto,  . Sandy, . 1396 62 171 
41 Ditto, ° Clay, . C 1°393 60 1:69 
42 Ditto, Silicious sand, «  Jes9il +) 62 1:76 
43 Red-straw white, Silicious sandy loam, 1°381 62 1°72 
44 Ditto, - Ditto, , 1392 62 173 
45 Ditto, 4 Calcareous, brashy, 
and shallow, 1362 61 1°61 
46 Ditto, Clay loam, . 1413 63 160 
47 Ditto, « Calcareous and sili- 
; cious sand, 1377 = 63 1:90 
48 Ditto, ‘ Calcareous clay, 1388 623 1:73 
49 Ditto, : Adhesive loam, 1386 661 171 
In this table we cannot fail to observe a certain de- 
gree of connection between the specific gravity and 
the weight per bushel in many cases. Thus speci- 
mens 2, 9, 21, 23, and 31 correspond in having low 
specific gravities and low weights per bushel, whilst 
several specimens of high specific gravity give also a 
good weight per bushel, as specimens 28, 38, and 
46. But on the other hand, in the greater number 
of instances the relation existing between these two 
circumstances is anything but clear: thus in several 
samples’ of the same weight per bushel, the specific 
gravity is widely different; we need only instance 
specimens 2] and 30. A glance at the table will 
supply many other such examples. 
‘* The quantity of water in the different parts of 
the wheat plant next requires notice. A certain 
amount of water appears to be natural to the grain, 
straw, and chaff of wheat. If, when damp, they are 
exposed in a moderately warm and dry atmosphere, 
they soon lose their superabundant moisture, be- 
coming to all appearance dry, but still retaining a 
certain and very considerable portion of water. This 
water is not, however, essential, although natural to 
them: for either of the three may by a heat under 
that of boiling water be perfectly dried without ap- 
parent injury or alteration of structure. The water 
in the grain varies between the limits of 9°5 and 
»13°5 per cent.: in the greater number of instances it 
is, however, between 10 and 12 per cent. The 
mean of all the specimens examined (62 in number) 
is found to be 11°69 per cent. In the straw the 
quantity of water ranges between 105 and 14:00 per 
cent.; the mean on 40 specimens being 1196. The 
