344 BULLETIN OF THE BUSSEY INSTITUTION. 
attitude of mind in which potassic fertilizers are regarded now-a- 
days, by farmers and investigators, in the high-farming districts of 
Holland and North Germany and in our own land of ‘* extensive” 
pastures and meagre mowing-fields. 
In the present paper I wish to enumerate some of the results 
which have been obtained in this country, more especially those 
that relate to matters which Professor Mayer has not noticed. I 
do not propose, however, to enter upon any formal criticism of 
Mayer’s work, or even to touch upon it, excepting in so far as it 
may serve occasionally to support or illustrate my story. 
A.— Carbonate of potash (wood-ashes) does good on many light 
lands by agglutinat:ng the particles of the soil in such manner that 
the condition of the land is improved as regards its capacity of re- 
taing moisture.. Conversely the potassic carbonate may do harm on 
clays — and on some loams whose particles are very finely divided 
(silt lands) — by increasing their plas‘icity, which is naturally only 
too pronounced. 
In so far as this particular effect of tempering earth is concerned, 
carbonate of soda produces similar results to carbonate of potash ; 
and the subject may readily be illustrated by a reference to the so- 
called alkali-lands of the West, whose peculiarities have been de- 
scribed by Professor E. W. Hilgard,* of the University of Cali- 
fornia, both in ‘* Silliman’s Journal” and in the ‘ Pacific Rural 
Press,” of San Francisco. To quote from Hilgard: ‘* Soils im- 
pregnated with alkaline carbonates may generally be recognized by 
their extreme compactness and their refractoriness under tillage, ~ 
and by the fact that they usually form ‘‘ low spots” in the general 
surface of non-alkaline land, where turbid clay-water dark with 
dissolved humus will lie for weeks after the higher land appears 
dry.” Agriculturally speaking, the trouble with such land is that 
it cannot be properly tilled by the ordinary mechanical appliances.f 
No matter how often it may be ploughed or harrowed such a soil 
will remain a mere mass of hard, broken clods; the particles of 
earth cannot be brought to the fine, crumbly, mellow condition 
* « American Journal of Science,” 1879 (3), 17%. 211. ‘‘ Pacifie Rural 
Press,” 1877-1880. 
+ As is well known to agricultural students, Professor Hilgard has over- 
come the difficulty, in cases where the amount of alkali is not too excessive, 
by chemical means; viz. by strewing gypsum enough on the land to decom- 
pose the alkaline carbonate. Drainage is of course to be resorted to also 
when possible. 
