160 
THE PHILOSOPHY AND USES OF BOTTOM-HEAT. 
stones, or broken free-stone, or rough brick rubbish, should then be placed on the 
partition thus made, and on that, again, there should be a layer of sawdust or 
bark which has lost all its fermenting properties, to plunge the pots in. This may 
be of any required depth. As a substitute for stone or slate to cover in the 
chamber, rude logs of wood, laid pretty closely together, may be found of service ; 
and an open gutter may be used instead of the common pipes for heating, if it 
should be more approved. 
To destroy wood-lice or other insects that may collect in the bark, sawdust, or 
whatever else is employed, the readiest plan is to pour boiling water over it when 
the plants are taken out for shifting, or when it is being turned over. Those 
disagreeable Fungi that likewise appear and spread so rapidly on bark, may be 
removed by the same means, even while the plants are in the bed, if the water be 
applied carefully, so as not to go near the roots. It will be of no use, however, if 
the water is not boiling at the time it is poured on. 
The kind of plants which we have had in view almost exclusively throughout 
this paper, are those which require the temperature of a stove. Of these, Orchi- 
dacese will stand first ; for they are perhaps the most benefited by bottom-heat, 
since plunging shelters their roots so thoroughly, and the atmospheric moisture 
obtained through watering the heating material is so congenial to their nature, 
while their notorious love of warmth is also thereby satisfied. From observation, 
and from the very nature of the plants, we can assert that no treatment induces 
such a beautifully healthy growth as that in which bottom-heat is a leading feature. 
Various other sorts of stove-plants are included in our recommendation. 
There is the tribe which has succulent habits, such as the Gesneras and Gloxinias 
already mentioned, and for which bottom-heat is mostly thought essential. Then 
there are the handsome shrubs, such as Ixoras, Rondeletias, &c, to which a little 
bottom-heat is exceedingly advantageous ; giving them altogether an improved 
aspect, and, by developing and ripening their wood more perfectly, increasing their 
production of bloom. There is further, the interesting class of climbers, which 
are often unfitted for blooming by being planted in some low corner, where their 
roots get too wet and cold. We know nothing so efficacious as bottom-heat (in 
connexion, of course, with other needful aids) in bringing climbers into a blooming 
state. It makes their wood healthy, and enables it to fulfil all its natural functions ; 
and where this is done, the plants are sure to flower well. 
We shall not, however, carry our enumeration to a greater length, as all stove- 
plants, whether coming beneath the divisions we have specified, or belonging to 
different tribes, will necessarily fall under the same rule ; and when we glance at 
existing collections of these objects, and observe the comparatively trifling advance 
in their cultivation which has been made of late years, we can hardly hesitate to 
attribute it, in great part, to the neglect of bottom-heat. It affects not our 
argument in this or any other case to say that plants are made to look very well, 
to grow luxuriantly, and to flower vigorously without the aids of the methods we 
