June, 1930 



E \' O L U T I O N 



Page sevexteex 



The Amateur Scientist 



A Monthly featuke conducted by Allan Strong Broms 

 The Plant Food Factory 



The leaf is the plant's laboratory 

 in which foods are synthetically pro- 

 duced. The chemist on the job is the 

 green coloring matter called chloro- 

 phyll. Its work is to sort out sunlight 

 rejecting the green light waves, which 

 are consequently reflected to our eyes, 

 and absorbing the other colors com- 

 posing white light, especially the red 

 waves. These happen to be just the 

 right length and frequency for effect- 

 ing certain chemical upbuildings out 

 of such raw materials as water (H20), 

 carbondioxide (C02), soil salts and 

 some nitrogen compounds. The re- 

 sulting complex chemical compound 

 contain stores of energy derived from 

 the sunlight. They serve as foods 

 for both plants and animals, releasing 

 their energy by a breaking down of 

 the complex compounds into those that 

 are simpler. This latter process is 

 really a slow burning, a combining 



of oxygen with other elements, par- 

 ticularly carbon, releasing energy 

 made manifest in living activities or 

 as heat. 



To detect the process of photosyn- 

 thesis, as the food upbuilding is call- 

 ed, perform this simple experiment. 

 Submerge an actively growing water 

 plant in a glass vessel and expose it 

 to the light. Bubbles will appear on 

 the leaf surfaces and rise through the 

 water. When the light is strong, the 

 bubbles will be numerous, as it dimin- 

 ishes, they diminish. The bubbles 

 consist of oxygen and may be collect- 

 ed by turning a glass of water over 

 above the plant without spilling. As 

 the bubbles rise, they will now slowly 

 fill the inverted glass. The oxygen as 

 it comes from the plant represents an 

 excess in the water and carbondioxide 

 which does not enter into the more 

 complex food compounds. That the 



gas is oxygen can be proved by thrust- 

 ing a match in it. The match will burn 

 with an unusual brilliancy. One can 

 even burn iron in it by dipping the 

 end of a steel wire into sulphur, set- 

 ting fire to it, and then immersing 

 it in the oxygen gas. 



The using up of food stuffs in the 

 process of living goes on night and 

 day in both plants and animals. It in- 

 volves the absorbing of oxygen and 

 the giving off of carbondioxide, just 

 the reverse of photosynthesis. It is 

 hard to detect in plants, especially 

 during the daytime because of the 

 more active reverse process which 

 hides it. But at night it becomes ap- 

 parent, for every part of the plant 

 continues this breathing, inhaling oxy- 

 gen, exhaling carbondioxide, while 

 the photosynthesis, depending 'upon 

 light, has entirely ceased. This is 

 the reason why it is unhealthy to 

 have plants in a closed bedroom. They 

 like the other living occupants, use 

 up the fresh air and pollute it with 

 their outbreathings. 



tinually taking place both within and around them, various exchanges of energy are not, it is evident, 



on the part of the substances of which they and ordinarily consequential enougli, or the energy is 



their neighbor molecules are naturally composed. not directed in suificiently telling ways, to so dis- 



Nor can they escape the buffeting action of the elec- tort a gene as to change its composition permanent- 



tromagnotic stresses and strains occurring through ly. Occasionally, however, such a change does oc- 



space in tlie field in which tliey lie immersed. These cur, and subsequent generations tell the tale. 



Research Laboratory of the University of Terras, Tnhere Professor Muller and associates experi- 

 ment with X-rays and fruit-flies to discover the roots of life. Note the hundreds of culture botths. 

 The results of these epoch-making experiments, shoxdng how mutations were increased 1500 percent, 

 -^'ill be described in the next issue of EVOLUTIOX. Bring this to the attention of your friends. 



