ON THE POTATOE. 323 



produce be eaten by hogs, or cows, or sheep (for all are equally fond of 

 potatoes), I entertain no doubt whatever that it will afford twenty times 

 as much animal food as the same extent of the same ground would have 

 yielded in permanent pasture ; and I am perfectly satisfied upon the 

 evidence of facts which I have recently ascertained that, if the whole of 

 the manure afforded by the crops of potatoes above-mentioned be returned 

 to the field, it will be capable of affording as good, and even a better, 

 crop in the present year than it did in the last ; and that as long a 

 succession of at least equally good crops might be obtained as the culti- 

 vator might choose, and with benefit to the soil of the field. Should this 

 conclusion prove correct, a very interesting question arises, viz. whether 

 the spade husbandry might not be introduced upon a few acres of ground 

 surrounding, on all sides, the cottages of day-labourers, to and from every 

 part of which the manure and the produce might be conveyed without 

 the necessity of a horse being ever employed. A single man might easily 

 manage four statute acres thus situated, with the assistance of his family ; 

 and if nothing were taken away from the ground except animal food, I 

 feel confident that the ground might be made to become gradually more 

 and more productive, with great benefit to the possessor of the soil, and 

 to the labouring classes, wherever the supply is found to exceed the 

 demand for labour. 



LXXI. ON THE MEANS OF PROLONGING THE DURATION OF VALUABLE 

 VARIETIES OF FRUITS. 



[Read before the HORTICULTURAL SOCIETY, May 3rd, 1831.] 



THE fact that all trees of the same variety of fruit, where each tree 

 partakes necessarily of one common life, are in their habits strongly 

 connected with those of the first original tree of the variety, is, I think, 

 placed beyond the reach of controversy. None can be made to produce 

 blossoms or fruit till the original tree has attained its age of puberty ; 

 and, under our ordinary modes of propagation by grafts and buds, all 

 become subject within no very distant period to the debilities and diseases 

 of old age. It is therefore desirable that the planter should know at 

 what periods of their existence varieties of fruits are most productive and 

 eligible ; and by what means (if any exist) the deterioration of valuable 

 varieties may be prevented or retarded. I was formerly inclined to 

 believe that grafts taken from very young seedling trees, as soon as the 



Y2 



