Messrs. Gladstone on the Growth of Plants in various Gases. 219 



as sulphurous acid or cyanogen, but that " its power is much 

 inferior/' They found that 23 cubic inches of carbonic oxide, 

 with five times the volume of air, had no apparent effect upon a 

 mignonette plant in twenty-four hours, but that it drooped 

 when removed from the abnormal atmosphere. We imagine that 

 the death of this plant must be ascribed to some other cause, 

 since we have kept a pansy in a healthy condition for four weeks 

 in 53 inches of pure carbonic oxide gas. 



It order to ascertain what effect different gases might have in 

 accelerating or retarding germination, and what compounds of 

 carbon were capable of affording nourishment to the young plant, 

 four onions just commencing to sprout were taken, weighed and 

 placed in vessels containing respectively carbonic acid, carbonic 

 oxide, coal-gas collected by displacement, and atmospheric air 

 containing eight per cent, of light carburetted hydrogen pre- 

 pared by the decomposition by heat of an alkaline acetate. The 

 four vessels containing these bulbs were each capable of holding 

 53 to 54 cubic inches of gas, and were inverted over water as in 

 the previous instances. The water employed to prevent access 

 of air to the vessel containing the carbonic acid was itself satu- 

 rated with the same gas ; that employed for the hydrocarbons 

 was an alkaline solution, so as to absorb any carbonic acid which 

 might happen to be present in the gas, or which might be gene- 

 rated by the growing root itself. A comparative experiment was 

 made with another onion placed under a glass shade under similar 

 circumstances as to light, heat, &c., but open to the atmosphere. 

 The onions selected had each a plumule of about half an inch 

 in length, and the experiments extended through the months of 

 April, May, and June. The onions in the atmospheres contain- 

 ing hydrocarbons grew rapidly, and put forth fresh roots. After 

 thirty days the plants were taken out of the coal-gas and car- 

 buretted hydrogen, as they had grown to the top of the vessels, 

 being at the time in a very healthy condition. The onion in air 

 grew, but not so fast. Those placed in carbonic acid and car- 

 bonic oxide stopped growing, and eventually became rotten. In 

 each instance they lost weight. 



In the early part of the year a crocus commencing to sprout 

 was placed in a jar containing 70 cubic inches of carbonic oxide 

 mixed with 100 cubic inches of atmospheric air, inverted over 

 alkaline water so as to absorb any carbonic acid that might be 

 formed. The rootlets of the bulb dipped into clear water. The 

 crocus grew and put forth abundance of long leaves, but it never 

 flowered. After remaining in this state for fifteen weeks, the 

 experiment was discontinued, and the bulb and plant were found 

 to weigh 285 grains, which was one grain less than at the com- 

 mencement of the experiment. The gas within the receiver 



