VOL. LXVII.] PHILOSOPHICAL TRANSACTIONS. 223 



of earth as they are generally planted in to be plunged into the bark-bed in the 

 common way ; that is, I put the pot of earth, with the pine plant in it, in the 

 pan full of water, and as the water decreases I constantly fill up the pan. I 

 place either plants in fruit, or young plants as soon as they are well rooted, in 

 these pans of water, and find they thrive equally well : the fruit reared in this 

 way is always much larger, as well as better flavoured, than when ripened in the 

 bark -bed. 1 have more than once put only the plants themselves without any 

 earth, I mean after they had roots, into these pans of water, with only water 

 sufiicient to keep the roots always covered, and found them flourish beyond ex- 

 pectation. In my house, the shelf I mention is supported by irons from the top, 

 and there is an intervening space of about 10 inches between the back wall and 

 the shelf. A neighbour of mine has placed a leaden cistern on the top of the 

 back flue (in which, as it is in contact with the flue, the water is always warm 

 when there is fire in the house) and finds his fruit excellent and large. My 

 shelf does not touch the back flue, but is about a foot above it ; and conse- 

 quently the water is only warmed by the air in the house. Both these methods 

 do well. The way I account for this success is, that the warm air always as- 

 cending to the part where this shelf is placed, as being the highest part of the 

 house, keeps it much hotter than in any other part. The temperature at that 

 place is, I believe, seldom less than what is indicated by the 73d degree of Fah- 

 renheit's thermometer, and when the sun shines it is often at above 100°: the 

 water the plants grow in seems to enable them to bear the greatest heat, if 

 sufiicient air be allowed ; and I often see the roots of the plants growing 

 out of the holes in the bottom of the pot of earth, and shooting vigorously in 

 the water. 



My hot-house, the dimensions of which it may be proper to know, is 6o feet 

 long, and 1 1 feet wide, the flues included ; 6 feet high in the front, and 11 feet 

 at the back on the inside of the house. It is warmed by 2 fires. A leaden 

 trough or cistern on the top of the back flue is preferable to my shelf, as in it 

 the pine plants grow much faster in the winter, the water being always warmed 

 by the flue : of this I have seen the great benefit these last 2 months in my 

 neighbourhood. It is not foreign to this purpose to mention that, as a person 

 was moving a large pine plant from the hot-bed in my house last summer, which 

 plant was just showing fruit, by some accident he broke off" the plant just above 

 the earth in which it grew, and there was no root whatever left to it : by way of 

 experiment I took the plant, and fixed it upright in a pan of water, without any 

 earth whatever, on the shelf ; it there soon threw out roots, and bore a pine- 

 apple that weighed upwards of 2 pounds. 



VOL. XIV. G G 



