Contagious Cattle Diseases in Yorkshire. 
179 
all the experiments which I had tried with potash salts for a 
number of years upon heavy soils, no appreciable result was pro- 
duced on the grass or root crops to which these salts were applied. 
Your experience, however, induced me last season to try a mix- 
ture of superphosphate with potash salts on some poor clay land 
in Kent, and the accounts which I received from several farmers 
who tried this mixture upon clover seeds on heavy land, and I 
may add also upon potatoes, are very satisfactory. I have myself 
seen the good effects which potash salts and superphosphate pro- 
duced on clover and grass on moderately stiff land in the neigh- 
bourhood of Bromley, in Kent, and I believe this mixture will 
probably be found beneficial for grass land on the poor clays in 
Staffordshire, and, generally speaking, on the bad clays of the 
Coal Measures. A close examination of these clays, if I am not 
mistaken, will show that there are some clays which are greatly 
deficient in potash, and on such poor clay soils the application 
of potash salts no doubt will be attended Avith beneficial results. 
I am glad to have this opportunity of modifying to some extent 
the opinion which I expressed on the strength of a more limited 
experience than I now possess, namely, that salts of potash are 
likely to be useful only on light land, for the experience I had 
last year fully confirms your own that there are clay soils as well 
I as light land which are benefited by the application of potash 
salts and superphosphate." 
It will have been observed that throughtout this article the 
means principally relied on for increasing our home production 
of meat are, an extended use of artificial manures on pasture land 
and of feeding-stuffs for cattle at grass. At the present prices of 
fat and lean stock, it will pay the farmer to adopt both systems 
simultaneously. The great difficulty is in making a beginning. 
The routine of years, possibly handed down for generations, cannot 
be broken through without a pang ; but such pangs seldom outlive 
the first favourable balance-sheet, and it may be confidently stated 
that for some time past the farmers who have made most money 
' are those who have paid as much attention to the improvement 
of their grass as to the growth of fine crops of corn or roots. 
Kirkhy Hall, Fehruary, 1872. 
V. — Tlie Records of Contagious Cattle Diseases in Yorkshire 
during the years 1870-71. By J. Dent DenT, M.P. 
[A Letter to the Editor.] 
" My dear Sir, — It has occurred to me that some readers of 
the Journal might be interested in the records of contagious 
N 2 
