0 jO . AnaJi/.^es of Ashes of Plavts. 
are equally open to tlia same objection on the small scale — that 
our specimens may be wet as well as larger quantities ; but were 
it so we should know it, for in each case we have ascertained the 
water contained in the specimen: that they should be found very 
similar in this respect is not to be wondered at, and is no proof 
of the constant state, as regards moisture, of a whole crop— for 
our specimens, being small, soon dry in a warm atmosphere, and, 
with free exposure to the air, to the extent which is natural to 
them. 
The method usually adopted of weighing large quantities of 
grain and straw to determine their relative proportion is, we con- 
sider, open to much objection in consequence of the varying con- 
dition of the straw as to dryness. 
The chaff of wheat is also capable of absorbing and retaining, 
unless freely exposed to the air, a considerable amount of moisture, 
and would materially tend in this way to increase the apparent 
amount of straw and chaflF in relation to grain. 
In pointing out these circumstances as likelj- to influence the 
accuracy of determinations on the large scale, we do not of course 
at all include those other sources of error which imperfect weighing 
apparatus and carelessness, or indifference on the part of those 
intrusted with the duty of ascertaining these particulars, would 
introduce. The general impression with practical men, with regard 
to the relative weight of grain and straw, woidd seem to be, that 
the latter is ordinarily double the former — at least such has been 
the answer which our inquiries on this point have usually elicited. 
In this statement they of course include the chaft, and spenk of 
the actual quantity of straw removed from the land, without 
reference to the stubble which is left behind. 
We will shortly allude to our own results obtained on the crops 
of the present harvest, premising that we are well aware that the 
dryness of the season, whilst it has had a favourable efTect upon 
the wheat as a grain crop, has at the same time I'endered the straw 
shorter, and consequently less in weight than in average years.* 
* In the account of the specimens we have given the relation of grain, 
straw, and chaff', in three different forms. By the insertion of the actual 
quantities in the weighings, we wish to show how much wiieatin each case 
has been operated upon. The per cenUxje is given as the ordinary and 
famihar method. We, however, prefer considering the grain as a fixed 
quantity, as 1000 for instance, and referring the weight of straw and chaff 
to this number; in this way tlie weight of straw and chaff of any one 
specimen is strictly comparable with that of another. 
The per centage is open to objection from there being three numbers; 
the alteration of any two causes the third to deviate, although in reality 
perhaps constant — this will at once be seen by rcfereucc to specimens 3, 
23, 32, 49. 
