illuminating qualities, or yielding gases more innocuous in respiration, or less 

 injurious to furniture, for it contains neither carbonic acid nor sulphuretted 

 hydrogen. 



The supply of this material is inexhaustible, and any anticipated demand can 

 scarcely enhance the price. It is now delivered at the Company's Works, in 

 Baltimore, at eighteen cents per gallon. Each gallon of the raw material may be 

 safely estimated to make one hundred cubic feet of gas from this machine. The 

 apparatus, as above described, with a gasometer of the capacity of a hundred 

 and thirty cubic feet, will contain an average of a week's supply, to an ordinary 

 family, the year round, and is sold at the Company's Works, in Baltimore, com- 

 plete, for $350. They are made, however, of any required capacity, and adapted, 

 in form and size, to the necessities of the space they are to occupy, and the require- 

 ments of the burners they are to supply. 



Of course these requirements and necessities are so varied, and so materially 

 increase or lessen the cost of the whole machine, that it is difficult to furnish a 

 tariff of prices suited to all occasions ; and persons intending to employ this appa- 

 ratus, will of course address the manufacturers, who have spent much time and 

 money to bring about the results now consummated. The principle and its appli- 

 cation through this machine, are now no longer a matter of mere experiment. We 

 congratulate the public on this new source of comfort being perfected, and brought 

 within the reach of country families. 



NIGHT TEMPERATURE. 



BY AMICUS, PHILADELPHIA. 



Facts have been found sufficient to demonstrate that it is the purpose of nature 

 to reduce the force which operates upon the excitability of vegetation at that 

 period of the twenty-four hours when, from other causes, the powers of digestion 

 and assimilation are suspended. As far as is at present known, that power is 

 heat, and, therefore, we must suppose that, to maintain, at night, in our hothouses 

 a temperature at all equal to that of the day, is a practice to be condemned. 

 Plants will, no doubt, lengthen very fast, at night, in a damp heat, but what is 

 produced at this time, seems to be a mere extension of the tissue formed during 

 the day, and not the addition of any new part; the spaces between the leaves are 

 increased, and the plant becomes what is technically and very correctly called 

 " drawn," for, as has been justly observed, " the same quantity only of material is 

 extended to a greater length, as in the elongation of a wire." 



Some observations made in the garden of the London Horticultural Society, a 

 few years since, place this in a striking light. Certain plants were placed for some 

 weeks in a stove, with a high night temperature supposed to average 69° ; the 

 rates of growth, in inches, showed that they grew as fast by night as by day ; but, 

 when the same kind of plants were grown in the open air, the growth was double 

 or treble by day what it was at night, and continued observation of many plants 

 produced the curious result that the total growth, by night, in the open air, was 

 119.07, and by day, 337.16. 



Thus we see that plants exposed to natural circumstances only made one inch 

 of growth by night, while they made three by day ; but that, on the contrary, 

 under bad artificial treatment, they grew equally day and nkjht. The inevitable 

 consequence of this inversion of natural growth, is immature or unripe wood, with 

 imperfect, ill-constructed buds, and a feeble constitution, incapable of bearin 

 shock of great falls of temperature. More especially, water accumulates i 



