ELECTRIC LIGHT. 



237 



sessing any authority to enter into negotiations, 

 returned to Cairo in July, and represented that 

 King John had given him a favorable recep- 

 tion, and informed him that he was desirous 

 of maintaining friendly relations with Egypt. 

 Early in October the Government was dis- 

 patching sixteen hundred troops to relieve the 

 garrisons on the Abyssinian frontier. The offi- 

 cial journal, a few days later than this, con- 

 tradicted rumors of a fresh outbreak of hos- 

 tilities on the frontier, and said that the rela- 

 tions between the two countries were not of a 

 hostile character. The Egyptian Government, 

 it is said, had made every effort, especially since 

 the accession of TevSk Pasha to the throne, 

 to remove all causes which might lead to a 

 conflict. 



The first meeting of the Egyptian Judicial 

 Reform Commission was held December 6th, 

 under the presidency of Riaz Pasha. Thirty 

 delegates of the powers who are represented 

 in the international tribunals were present. 

 The committee resolved that the status quo 

 should be maintained until the 1st of February 

 ensuing, unless the work of the committee 

 should be concluded at an earlier date. 



ELECTRIC LIGHT, VEGETATION UNDER 

 THE. The success of Dr. Siemens in producing 

 healthy vegetable growth under the electric 

 light, contradicts effectually the conclusion of 

 Sichs, that the action of light in promoting 

 plant-growth is owing to properties favorable 

 to chemical changes which are peculiar to solar 

 light. The chemistry of plant-life is less un- 

 derstood than the chemical processes in animal 

 physiology. The haemoglobin of the blood 

 enters as an active agent in oxidation : when 

 extracted from the associated albuminoid mat- 

 ter in a pure crystalline state, it is capable of 

 combining with oxygen and again liberating 

 the oxygen, precisely as it does in the living 

 body. The analogous process in vegetation is 

 as dependent upon chlorophyl ; but the part 

 played by chlorophyl is more mysterious. 

 Extracted from green leaves with alcohol or 

 ether, and shown to be chemically identical 

 with the coloring matter of the plant-cells by 

 its giving the same complex spectrum, the 

 chlorophyl exhibits no deoxidizing power de- 

 tached from the vegetable protoplasm. 



From the fact that the rays of light which 

 are absorbed by chlorophyl are not those 

 which are active in exciting cell-formation, 

 since light which has passed through a solution 

 of chlorophyl has been found just as efficient 

 in producing vegetable growth, and from indi- 

 cations that the absorbed rays have the con- 

 trary effect of causing an excessive oxidation 

 and a disruption of protoplasm, Pringsheim 

 supposes, in the absence of any proof of an 

 active agency of the green substance in deconir 

 posing carbonic acid, that this simply acts as a 

 screen to protect the cells from the too vigor- 

 ous action of the rays which promote oxida- 

 tion, and that it is the living protoplasm which 

 under the influence of the transmitted rays per- 



forms the functions of liberating O from CO 3 , 

 and^ uniting the elements of the starch-cells. 



Siemens propagated quick - growing plants, 

 such as cress and mustard. For the purposes of 

 comparison they were separated into lots, one 

 of which was exposed to electric light alone, 

 one to daylight alone, one to daylight and to 

 electric light in the night-time, and one kept 

 in darkness. He experimented in the open air, 

 and afterward in a heated greenhouse, with a 

 lamp constructed for continuous currents with 

 two carbon electrodes, equal to 1,400 candles. 

 The light was demonstrated to be equal or 

 nearly equal to daylight in exciting chlorophyl- 

 formation and deoxidation of carbon dioxide, 

 and in promoting all manifestations of healthy 

 vegetable life. Where the normal exposure to 

 daylight was supplemented by electric lighting 

 at night, the plants throve much more luxu- 

 riantly than under the influence of sunlight 

 alone. The electric lamp was observed to ex- 

 cite the phenomena of heliotropism, the erec- 

 tion of leaves after they had drooped for re- 

 pose at night, the opening of flower-buds, and 

 all the effects of sunshine. In a palm-house 

 the lamp was placed in a position correspond- 

 ing to that of the sun at mid-day, and lighted 

 for eleven hours each night for a week. The 

 plants under the double illumination assumed 

 a more vigorous appearance, the leaves took 

 on a darker and fresher hue, and the coloring 

 of the flowers appeared to be more brilliant 

 than usual. The electric light seemed to be 

 more efficacious in bringing out flowers than 

 sunlight. The effects of the light were most 

 striking upon the plants which were nearest. 



Dr. Siemens drew from his experiments the 

 following conclusions: Electric light is effective 

 in causing the formation of chlorophyl in 

 leaves and in exciting vegetable growth; an elec- 

 tric lamp of 1,400 candles' brightness, placed at 

 the distance of six and a half feet from grow- 

 ing plants, is equal in its effects to average day- 

 light; the carbonic acid and nitrogenous com- 

 pounds generated in the electric arc are not 

 sufficient in quantity to injure plants in an in- 

 closed room; plants under the influence of 

 electric light appear to be able to sustain a 

 degree of heat which would otherwise wither 

 them ; plants exposed to sunlight during the 

 day and to electric light during the night, show 

 an increased vigor and rapidity of growth, 

 proving that a period of rest during the twenty- 

 four hours is not required in vegetable life. 

 The latter deduction is confirmed by prolonged 

 observations made by Dr. Schiibeler, of Chris- 

 tiania, upon the effects on vegetation of the 

 uninterrupted sunlight of the Arctic summer. 

 He found that plants from lower latitudes ac- 

 climatized in Norway develop a larger and 

 more rapid growth, that they bear heavier 

 seeds, and that the pigments of their flowers 

 and leaves acquire deeper and richer hues. 

 The aromatic properties of plants and fruits 

 also are augmented to a remarkable degree : a 

 much larger percentage of essential oils can be 



