On the St. Jolm's-Dmj Rye. 
357 
is also more than probable that Messrs. Peter Lawson and Sons, 
No. 1, George the Fourth's Bridge, Edinburgh, the seedsmen to 
the Highland Society, may be able to supply the article required. 
For Cooper's early broad-leaved rye, I recommend an application 
to Mr. Thos. Cooper, of Ardleigh Wick, near Colchester, he being 
the only person whom I certainly know capable of supplying that 
valuable variety, the origin and history whereof I hope that he or 
some other able agriculturist will communicate to the public. 
Should any farmer raise a supply of seed of the St. John's- 
day rye, for his own use, I strongly advise him to sow a part, but 
not the whole, so soon after the harvest as he can get it threshed, 
and to reserve one half of it to be sown in the following summer ; 
for, however fine the season, and however warm and forward his 
land and situation, he will scarcely get it threshed out till near 
the end of July, which is a month later than the best season for 
sowing it, if he would see the plant in perfection. If he will sow 
the reserved portion at the Midsummer following, and is not 
thereafter satisfied with his produce, let him then impute to the 
author that he has been grossly misled. 
XXV.— 0/i the Potato Disease. By F. J. Graham, B.A., F.L.S. 
Prize Essay. 
Of the innumerable hostile agents with which the cultivator of 
the soil has to contend, some he is able to keep in check by the 
ordinary course of husbandry; others have from time to time 
engaged the attention of men eminent in various departments of 
science. Still there is mischief in the field, the origin of which is 
not yet " dreamt of in our philosophy." Such was, perhaps still 
is, the subject of the present Essay — the Potato Disease of 1845, 
notwithstanding the most minute investigations have been made 
by some of the ablest Professors both in this and foreign countries 
in order to ascertain its real character. But probably few subjects 
of the kind ever presented greater diflficulties, its cause being im- 
perceptible, its attack inevitable, its remedy apparently impos- 
sible. 
The first intimation I received of it was a mere rumour about 
the rith of August, 1845 ; and on the 16th this was confirmed by 
Dr. Bell Salter in the " Gardener's Chronicle." I had then used 
my ashleaf kidneys and one bed of Fox's seedlings, without finding 
any sign of disease ; but ten days afterwards, on taking up ano- 
ther bed of Fox's on the south side of a path which divided them, 
2 bushels on two rods were more or less affected. 
When the first bed was dug the haulm had not faded, but that 
