926 



SCIENCE. 



[N. S. Vol. XVI. No. 415. 



The idea of the poisonous nature of this 

 gas may easily be subjected to experimen- 

 tal examination. It would appear easy to 

 expose a plant to an artificial atmosphere 

 made up to different partial pressures of 

 carbon monoxide, to expose it in such at- 

 mosphere to various conditions of warmth 

 and illumination and to note the effect pro- 

 duced. It would seem possible to examine 

 a great variety of plants in that way, to 

 try both aerial and aquatic forms, and in- 

 deed to test the matter exhaustively. It 

 must be borne in mind, however, that the 

 solubility of carbon mc loxide in water is 

 extremely small, and that there may be a 

 great difficulty in getting it brought within 

 the scope of the influence of the living sub- 

 stance on that account. It must neces- 

 sarily be in solution in the cell sap before 

 it can affect the activity of the chloroplast. 

 Even the relations of solubility are not, 

 iowever, outside the range of experiment, 

 and it may be that the slightly acid cell 

 sap has not the same peculiarities as water 

 as a solvent for the gas. 



It is important again to take into ac- 

 count in such work the factor of sunlight, 

 on which the power of photosynthesis de- 

 pends. Should carbon monoxide prove 

 capable of serving as a basis for the forma- 

 tion of carbohydrates, the question would 

 arise. Is the activity of the chlorophyll in 

 sunlight confined to the preliminary forma- 

 tion of carbon monoxide from the dioxide, 

 or is the energy derived from the light 

 brought to bear upon the subsequent con- 

 structive processes? We have little or no 

 accurate information as to the way in which 

 the energy is utilized after absorption by 

 the chlorophyll. 



This opens up a very important but very 

 difficult line of work, which brings home 

 to us the intimate dependence of vegetable 

 physiology upon physics. The absorption 

 of energy from without, in the form of the 

 radiant energy of the solar rays, is certainly 



a fact, and to a certain extent we can pic- 

 ture to ourselves the way in which it is 

 secured. The spectrum of chlorophyll 

 shows us a number of absoi'ption bands 

 whose position corresponds with the posi- 

 tion in the spectrum of the places where 

 oxygen is liberated in photosynthesis. But 

 the transformation and applications of 

 energy in the body of the vegetable organ- 

 ism need much closer examination. The 

 intimate relationship between the ditrerent 

 manifestations or forms of energy and the 

 ways in which they can be transformed 

 into one another, have been very minutely 

 scrutinized in recent times. What then 

 should hinder us from learning something 

 much more definite than we at present know 

 about these transformations in the role of 

 vegetable life? The electrical phenomena 

 connected with the movements of the leaves 

 of the Venus 's fly-trap {DioncECi muscipula) 

 have been examined with considerable com- 

 pleteness by Burden Sanderson, and we 

 have learned that the vegetable and animal 

 organisms show considerable similarities in 

 this respect. Recently again Bose has 

 made important contributions to the subject 

 of the electrical responses to stimulation 

 that can be observed under particular con- 

 ditions. A promising beginning has thus 

 been made, but only a beginning. The 

 electrical condition of the normal plant un- 

 der different conditions of rest and activity 

 has still to be investigated. If we return 

 to the subject of photosjTithesis and the 

 work done by the chloroplast, may we not 

 hope to discover something about the trans- 

 formation and utilization of the radiant 

 energy associated somehow with this struc- 

 ture? Considering the relations between 

 the manifestations of energy which we ap- 

 preciate respectively as light and electricity, 

 it does not seem wildly improbable to im- 

 agine that the energy absorbed as the 

 former may lead to a possible electrolysis 

 of carbonic acid under the influence of the 



