New YorK AGRICULTURAL EXPERIMENT STATION. Seal 
The objections to the method are mechanical in nature—they 
are the objections arising from a faulty technique. Seeds gener- 
ally take up water, though there are very considerable differences 
between individual seeds of the same lot with regard to the 
rapidly with which they do so. For this reason the method of 
salt solutions as commonly applied does not yield separates 
exactly comparable; but the differences in specific gravity due to 
unequal absorption of water are at most only a few one hundreths 
of unity, and for practical purposes may be to a considerable 
extent disregarded. Another objection which has been urged 
against the method of salt solutions is that it is slow and trouble- 
some of application; but it is no more so than is that of immers- 
ing oats in hot water as a treatment for oat smut. This latter 
is recognized as an agricultural practice in good standing. 
The logical applications of the methods of separates and of 
samples are fundamentally different. As has already been 
remarked, the method of separates is suited properly for distin- 
guishing between different individual seeds in the same lot. It 
is analytical. The method of samples is not analytical, but is 
appliable in judging the comparative merits of two lots of seeds. 
It does not take cognizance of individual differences among the 
seeds; it judges the average value of the whole lot. 
THE METHOD OF SAMPLES. 
The method of samples has been applied in several ways. A 
simple and elementary form of it was used by Grandeau. He 
placed a certain number of seeds in a small graduated cylinder 
of water and noted the amount of water displaced. From this 
and the weight of the seeds previously determined the specific 
gravity could be computed. This method is quick of operation 
and for this reason is subject only to comparatively small error 
on account of absorption of water by the seeds. 
The method which has been most used in exact investigations 
in seed selection according to specific gravity is the pycnometer 
method. This method gives very exact results but is slow of 
application, even in the laboratory. In gardening practice it is 
utterly out of the question. 
Determinations by this method were at first made in distilled 
water, but the use of water was soon abandoned for the reason 
