For May, l')23 



121 



Stimulating Plant Growth With Carbon Dioxide 



DR. E. BADE 



T 



1 1 E introduction of carbon dioxide gas to plants 

 inclosed in glass vessels to stimulate growth is quite 

 old, but no success was ever derived from such a 

 process, the plant invariably becoming abnormal. Such 

 experiments have been carried out since the 18th centrury 

 when Lavoisier discovered that the process of respiration 

 in plants was analogous to the process of combustion and 

 when Ingenhouss proved that plants could revivify the 

 most stagnant air in a few hours of sunlight. 



More recent investigations have conclusively proven 

 that plants breathe just like animals, that is, they take up 

 oxygen and give off carbon dioxide. This process, vi'hich 

 takes place both day and night, is most noticeable at the 

 latter period. In the day time, while manufacturing 

 starch in the leaves with carbon dioxide, taken in as a gas 

 through tiny leaf openings, the stomata, and water, taken 

 up through the roots, oxygen is given off as a waste or 

 by-product, but normal respiration still takes place in 

 spite of this fact although the gas taken up in breathing 

 is nowhere nearly as much in tjuantity as that wdiich is 



plants not only growing faster, but more luxuriantly as 

 well. This process is essentially nothing more than feeding 

 the plant through the leaf by providing the raw materials 

 necessary for the manufacture of its structure, a process 

 of '"fertilization" comparatively inexpensive, and dis- 

 tinctly new. 



In the exiieriniental plant of the "Riedel P^ertilizing 

 Process Company" of Elizabeth, N. J., this process has 



Colcus gassed. A ot gassed 



been tested for its practical value. Two exactly similar 

 greenhouses of the usual type were built, but one was 

 provided for the distribution of carbon dioxide gas, the 

 other was used as a control house. The results obtained 

 are exceptional. The gassed plants are thick, more mas- 

 sive, robust, vigorous, and healthy in every way, while 

 the same plants in the control house which were not pro- 



Dlagram slwicijig distribution of carbon dioxide 



given off. This significant fact was only too seldom 

 taken into consideration in former times wdiile conducting 

 gas experiments with plants, it being the source of the 

 greatest errors. 



Today it has been established that starch is manufac- 

 tured with the aid of chlorophyll, the green coloring- 

 matter of the leaves which act like a catalyst. 



1— H,0 (water) + CO, (carbon dioxide) = HXO. (Carbonic 

 acid). 

 2— 2H,C0, = 2CH,0., (formic acid) + O, (oxygen). 

 3— 2CH..O. = 2CH.6 (formaldehyde) + O... 

 4— 6CH.,0 =C„H,,0„ (grape sugar). 

 S— C„H,,0„ = C„H,„05 (starch) -|- H=0 (water). 



The water and the carbon dioxide come together in the 

 leaf, and, under the influence of chlorophyll, carbonic acid 

 is produced. But this reaction only occurs under the 

 chemical influence of light rays, it does not take place at 

 night. From the carbonic acid, formic acid is produced, 

 which in turn is changed into formaldehyde. Each of 

 these last two reactions produce a by-product which 

 escapes through the stomata, it is oxygen gas. Six 

 molecules of the formaldehyde are condensed whereby 

 grape fruit sugar is formed. This, by a process of poly- 

 merization, is changed to starch, water being extracted 

 by this transformation. 



Slightly increasing the quantity of carbon dioxide 

 available for plant food, has given remarkable results. 

 The subjection of growing plants to doses of this gas at 



■voided with artificial gas-nourishment, are small, more or 

 less straggly when compared to the others, develop fewer 

 leaves, and their root system is longer, less compact and 

 dense. 



The gas is produced by the furnace used to heat the 

 greenliouse. \Mien the house is to be gassed, which is only 

 ncessary at intervals, the short length of pipe leading to 

 the flue, is closed, and the gas led through pipe A to the 

 first scrubber. Two of these stand just outside of the 

 house. The gas, which enters at the bottom, passes over 

 coke H placed upon a grate G. From pipe 1 a fine 

 spray of water is passed over the coke, the waste water 

 {Continued on page 124) 



