10 
PHENOMENA OF WINTER. 
The true period of the increments of solar influence may he dated from the 3rd 
or 4th day of January, and then the attention of the forcing gardener ought to be 
more and more roused. Our treatment of plants under glass must, of necessity, he ii 
regarded as artificial, since every ray is more or less obstructed or modified. The 
science of this branch of gardening, should therefore be conducted by observation 
and experience; effects should be closely attended to, results noted, and every 
reference to what is termed nature be abandoned, unless it simply consist of a 
geographical knowledge of the situation, climate, and general or mean temperature, 
and its extremes, in the native climes. Glass exerts a novel and modifying 
influence, upon every concomitant of plant culture ; the constitution of the subjects 
within a forcing-house, is affected with respect to the nature of the heat, the light, 
the condition of artificially-raised moisture within the building, whereby also the 
transpiration from the oscular pores of the leaves is variously affected ; and here, at 
this very point, we beg to offer, with all due respect for authorities, the suggestion, 
that most of the theories concerning the absorption of gases by the leaves, the 
transpiration of oxygen, the decomposition of carbonic acid, and the fixation of 
deposited carbon in the organism, (when founded upon experiments made only in 
unnatural situations, under glass, in close vessels, and in circumstances foreign to 
those of nature), cannot be deemed conclusive. Such theories remain subject to 
doubt, inasmuch as they lead to no certain knowledge whatsoever of the phenomena, 
that result from the energy of the great natural agents, exerted under cir- 
cumstances perfectly and purely natural. 
Every one ought to observe, and study the influence of light, during the 
recession and gradual advance of the sun ; the chemical colouring and attractive 
influences are distinct, and although we may never discover the modes in which the 
components of light act, yet, being sure of the effects, it is very possible to trace 
their progress. 
We now cannot further dilate, as it is required to take a cursory view of 
the agency of artificial heat, at a season when the economy of means is of the more 
consequence, inasmuch, as that implies also, the most perfect combustion of the 
articles employed. We will “begin at the beginning,” and extract a few passages 
from the inaugural Lecture, delivered very lately by Dr. W. A. Miller, at King’s 
College, which is reported in the Pharmaceutical Times of December 19th and 26th. 
“ When a pound of charcoal ” it states “is burned, when it combines with oxygen 
from the air, it gives out a certain amount of heat, which, from careful experiment, 
appears to be sufficient to convert thirteen pounds of water at 60 degrees — the 
ordinary temperature of the air — into steam at 212 degrees, the boiling point of 
water : in other words, it will boil away thirteen pounds of water ; and more than 
the heat sufficient to effect this, no ingenuity can make it furnish.” Here the 
amateur reader, who possesses hot water pipes or channels connected with a boiler, 
might, with great advantage, calculate the net contents of his machinery in gallons, 
and the bulk or weight of the carbonaceous material consumed to bring the water to 
