BOTANY. 325 



and algae in various localities, and especially as their being the cause 

 of various coincident phenomena ; whereas, viewed in another light, 

 their presence may, in most instances, be considered accidental, in the 

 ordinary acceptation of the word." 



Dr. C. T. Jackson alluded to experiments made of passing the air 

 containing these fungi through concentrated sulphuric acid ; no in- 

 fusoria were found in vessels to which air could only gain admittance 

 to a vegetable infusion through this medium, while they were abun- 

 dantly found in infusions to which air had free access. These results 

 confirmed Dr. B.'s statements. 



OBSERVATIONS ON THE GROWTH OF PLANTS IN ABNORMAL 



ATMOSPHERES. 



As oxygen is the most important constituent of the atmosphere, so 

 far as animal life is concerned, so it is on the carbonic acid, ammonia, 

 and aqueous vapor that the vegetable world is eminently dependent. 

 Do the oxygen and nitrog-en of the air play no important part in the 

 process of vegetation? The following experiments, with a view of 

 settling this and similar inquiries, have been published by the Messrs. 

 Gladstone : A pansy lived for 24 days in an atmosphere of hydrogen, 

 containing 5 per cent, of carbonic acid ; one similarly placed in an at- 

 mosphere of common air remained healthy for a longer period. Five 

 onions just commencing to sprout were severally placed in carbonic 

 acid, carbonic oxide, coal gas, air containing 8 per cent, of light car- 

 buretted hydrogen, and ordinary atmospheric air. The germination 

 in the first two was entirely stopped ; while the hydrocarbons appeared 

 to considerably accelerate the growth of the vegetable. The plants 

 in each case lost weight. A pansy in flower, a young stock, and a 

 grass plant were placed in pure nitrogen gas. The first two soon died, 

 but the grass was left growing a month after the commencement of the 

 experiment. Another pansy was placed in a mixture of hydrogen and 

 oxygen gases, in the proportion requisite to form water. In order to 

 imitate the balance which exists in nature between animal and vegeta- 

 ble life, some flies were introduced, along with some sugar to serve as 

 their food. No change for the space of two weeks was observed in 

 this plant. Owing to the light specific gravity of the mixed gases, 

 the flies were unable to mount on the wing, or make the usual buzzing 

 noise ; but the substitution of hydrogen for nitrogen in the atmosphere 

 had no marked effect upon their breathing, thus confirming the obser- 

 vations of Reynault by an instance drawn from Articulata. London 

 Chemist* Oct. 



At the British Association, Mr. Daubeny stated, that he had ferns 

 growing in an atmosphere containing one per cent, of carbonic acid in 

 excess above that ordinarily contained in air , and although it was 

 thought similar ferns growing under the same conditions, but without 

 carbonic acid in excess, were the most luxuriant, it appeared that they 

 thrived well in this atmosphere. Ferns supplied with water contain- 

 ing one per cent, of carbonic acid grew much more luxuriously than 

 those which were supplied with pure water, so that the conclusion 



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