308 



ON THE CULTURE 



obliges the gardener to give the tan frequent turn- 

 ings, in order to promote its heating. These fre- 

 quent turnings, not to mention the expense, are 

 attended with the worst consequences ; for by the 

 continual moving of the pots backwards and for- 

 wards, the Pines are exposed to the extremes of 

 heat and cold, whereby their growth is consider- 

 ably retarded ; whereas, when leaves are used, the 

 Pines will have no occasion to be moved but at 

 the times of potting, &c. — The Pines have one 

 particular advantage in this undisturbed situation; 

 their roots grow through the bottoms of the pots 

 and mat amongst the leaves in a surprising man- 

 ner. From the vigour of the plants, when in this 

 situation, it is highly probable that the leaves, even 

 in this state, afford them an uncommon and agree- 

 able nourishment. 



Thirdly, There is a saving in point of expense, 

 which is no inconsiderable object in places where 

 tan cannot be had but from a great distance, as is 

 the case here, the article of carriage amounting to 

 ten shillings for each waggon-load. Indeed this 

 was the principal reason that first induced me to 

 make trial of leaves. 



My last ground of preference is the consideration 

 that decayed leaves make good manure j whereas, 

 rotten tan is experimentally found to be of no 

 value. I have often tried it both on sand and clay, 

 also on wet and dry lands, and never could dis- 

 cover, in any of my experiments, that it deserved 

 the name of a manure ; whereas, decayed leaves 



15 . 



