Diseases of the Potatoe. 27 
On the same day I put fourteen potatoes whole, and fourteen 
cut into fifty-six sets, into a deep box, filled with dry mould. 
The remaining fourteen whole and fourteen cut, I put into 
another box filled with modst carth, and which was watered 
from time to time. At the end of three weeks, all the plants, 
with the exception of five sets, made their appearance. ATI 
this time the dry box had been kept from moisture. On the 
21st of July, however, I allowed it to be moistened with 
heavy rain, and on the 28th of July, I took up and extracted 
starch from the whole. Before doing so, however, I weighed 
the several lots, and what seemed to me curious was, that 
each lot of the whole potatoes had gained eight ounces ; while 
each lot of the ewé ones had lost six ounces of its weight, and 
of their number ten did not vegetate. The sprouts from 
the whole potatoes weighed four ounces, and those from 
ithe cut only two ounces. Yet the starch from the twenty- 
eight cut potatoes weighed but two ounces, and that from the 
twenty-eight whole potatoes nine ounces, being exactly the 
produce in starch of half that number, which was made into 
starch at the commencement of the experiment.” 
Louden, in his Encyclopedia of Agriculture, says: “The 
diseases of the potatoe are chiefly the scab, the worm, and 
the curl. The seab or ulcerated surface of the tubers, has 
never been satisfactorify accounted for; some attributing it 
to the ammonia of horse dung; others to alkali; and some 
to the use of coal ashes. Change of seed and of ground are 
the only resources known at present for this malady. The 
worm and grub both attack the tuber, and the same -preven- 
tive is recommended. 
The same causes which have been assigned to a total or 
partial failure of the potatoe in numberless instances, and to 
a most distressing extent in Ireland, have existed since the 
cultivation of the potatoe commenced, but without the effects 
deplored, which have only prevailed within a very recent 
