BOTTOM HEAT. 
107 
3 rtain that, during every process of decay — (the result of fermentation) — 
aencies of prodigious power are exerted : water is decomposed, a galvanic energy 
) displayed in the progressive development of the elements oxygen, hydrogen, 
itrogen, and in new combinations, forming hydro-carbons, carbonic acid, 
mmonia, &c., all essential to vegetation ; and these facts, which now are placed 
eyond reasonable doubt, tend to repudiate the opinion that the efficiency of 
ottom-heat is dependent solely upon increase of temperature. In a word, we may 
rfely infer that the process of radification is the result of electro-chemical 
ttraction, while that depends upon elemental disturbance. 
So far, it will be evident that we are constrained to favour the old fermenting 
! ledium ; but, alive as we must be to its inconveniences, we inquire whether the 
ew and cleanly bed resting over the tank would not suffice for all the processes of 
ropagation, and also to maintain the ample verdure and health of such rooted 
lants — as for instance, the Gardenias — which demand the appliance of moist and 
rarm substances to the surface of their pots? Were charcoal-powder always 
raployed, with sand sufficient to give it texture and firmness, we have little doubt 
liat the roots would emerge, and revel in the bed ; and no scalding or burning 
/ould result from the violent extrication of ammoniacal gases. And although in 
lie event of protruded roots, the luxuriance of vegetation might not equal that 
reduced by the tan or leaf bed, yet not only do gardeners object to this rooting 
3r the reasons before assigned, but they ought on every account to prefer cleanness 
^nd security, provided they are not purchased at the expense of a positive injury. 
A tank alone will not be sufficient for hothouse or even pit culture ; we must 
ave atmospheric moisture and heat ; therefore from the returning channel or 
, utter of the tank a connected pair must be continued in front, by the end, and 
.;enerally at the back of the erection, so as to convey the flow- water ; and a cor- 
lesponding “ return” stream, till the latter terminate in the receiving pipe of the 
loiler ; and then, if these channels be regulated by sluices across the watercourse, 
nd by sliders at the top, both correctly adapted and moveable, any degree of 
laoisture may be commanded and regulated. 
We now invite our intelligent readers to observe, and decide for themselves, 
or such are the conveniences of the hot-water tank-plunging system, that we 
liould regret extremely to see it abandoned for one which, for years, has been 
troductive of nuisances of the most serious character. A further remark, and that 
I painful one, remains to be made ; the vapour of a tank-house is not found to bear 
, ut the assertion that it will afford ample protection against the Acarus, or plant- 
*'pider. We have very lately seen an entire collection of Gardenias the prey to 
housands of this pest ; and now, as sulphur also is found utterly valueless, we 
,»3ar that there is no remedial application, and that the gardener must trust to 
igilance alone. 
