March 1 1, 1880] 



NA TURE 



457 



14 feet in. (S'62in. X 14-42 m. X .','42) ui height. In the 

 centre of this house a banana palm and a few other small palm- 

 trees are planted, the sides of the house all round being occupied 

 with a considerable variety of flowering plants. The electric 

 light was fixed as high as practicable at the south corner of the 

 house, in order that its rays might fall upon the plants from a 

 direction and at an angle coincident with those of the sun during 

 the middle of the day. The temperature of the house was 

 maintained at 65° F., and the electric lamp was kept alight 

 from S P.M. to 6 A.M., for one week, from February iS to 

 February 24, excepting Sunday night. The time was hardly 

 sufficient to produce very striking effects, but all the plants con- 

 ti rued to present a healthy appearance. Of three Alicante 

 vines, the one nearest the electric light made most progress, and 

 the same could be said of the nectarine; and roses. It was 

 observed that other plants, such as geraniums, continued to 

 exhibit a vigorous appearance, notwithstanding the heat of the 

 place. This experiment is of importance in showing that the 

 electric light, if put into conservatories or greenhouses, does not 

 injure the plants, but rather improves their appearance and 

 growth. The leaves assume a darker and more vigorous ap- 

 pearance, and it seems that the colouring of the flowers becomes 

 more vivid, but a further period of time is necessary to establish 

 this observation absolutely. 



I decided to try the effect of electric light as a means of pro- 

 moting growth in the open air and under glass at the same time. 



The regulator was put back into its first position, 2 metres 

 above the ground, with a sunken melon house on one side, and 

 a sunken house containing roses, lilies, strawberries, and a 

 variety of other plants on the other. The space of ground 

 between these, about 1 metre broad and 7 metres long, was 

 covered with boxes sown with early vegetables, including 

 mustard, peas, beans, and potatoes, and in order to prevent cold 

 winds from injuring the plants, low protecting walls were put 

 up across the openings of the passage between the two houses. 



Some weeks must elapse before any absolute results can be 

 given, but growth is evidently promoted under all these various 

 circumstances. In order to test this clearly, a portion of the 

 plants both under glass and in the open air are shaded from the 

 electric light without removing them from their position of equal 

 temperature and exposed to solar light during daytime. The 

 effect upon the flowering plants is very striking, electric light 

 being apparently more efficacious to bring them on than daylight. 

 Although the amount of heat given off from the electric arc is 

 not great compared with a gas flame (giving off its products of 

 combustion), yet the rays of intense heat of the arc counteract 

 that loss of heat by radiation from the leaves into space, which 

 during a clear night causes hoar frost. For this reason I expect 

 that electric light may be usefully employed in front of fruit 

 walls, in orchards, and in kitchen gardens, to save the fruit-bud 

 at the time of setting; and in this application electric light will 

 probably be found a useful agent not only to promote rapid 

 growth, but to insure a better yield of fruit. 



The experiments seem to lead to the following conclusions : — 



1. That electric light is efficacious in producing chlorophyll in 

 the leaves of plants, and in promoting growth. 



2. That an electric centre of light, equal to 1,400 candles, 

 placed at a distance of 2 metres from growing plants, appeared 

 to be equal in effect to average daylight at this season of the 

 year, but that more economical effects can be attained by more 

 powerful light centres. 



3. That the carbonic acid and nitrogenous compounds gene- 

 rated in diminutive quantities in the electric arc, produce no 

 sensible deleterious effects upon plants inclosed in the same 

 space. 



4. That plants do not appear to require a period of rest during 

 the twenty-four hours of the day, but make increased and 

 vigorous progress if subjected during daytime to sunlight and 

 during the night to electric light. 



5. That the radiation of heat from powerful electric arcs can 

 be made available to counteract the effect of night frost, and 

 is likely to promote the setting and ripening of fruit in the 

 o; en air. 



6. That while under the influence of electric light plants can 

 sustain increased stove heat without collapsing, a circumstance 

 favourable to forcing by electric light. 



7. That the expense of electro-horticulture depends mainly 

 upon the cost of mechanical energy, and is very moderate where 

 natural forces of such energy, such as waterfalls, can be made 

 available. 



Since writing the above my attention has been drawn to an 



article in Nature, vol. xxi. p. 311, giving interesting observa- 

 tions by l>r. Schiibeler, of Christiania, on" The Effect of Unin- 

 terrupted Sunlight on Plants in the Arctic Regions." These 

 observations fully confirm the conclusion indicated by my experi- 

 ments with electric light. Not only are plants able to grow- 

 continuously, according to Dr. Schiibeler, but when under the 

 influence of continuous light, they develop more brilliant flowers 

 and larger and more aromatic fruit than under the alternating 

 influence of light and darkness, whereas the formation of sugar 

 appears to be dependent chiefly upon temperature. 



It would follow from these observations, that with the aid of 

 stoves and electric light, fruit, excelling both in sweetness and 

 aroma, and flowers of great brightness, may be grown withmt 

 solar aid. Dr. Schiibeler mentions that in removing an acacia 

 plant from the dark, and placing it under the influence of the 

 Arctic midnight sun, the leaves opened slowly, and it is interest- 

 ing to observe that the same effect took place when an Acacia 

 Lophantha was placed (in the open air) under the influence of 

 my midnight lamp. 



PREHISTORIC ANTIQUITIES OF THE 

 AUSTRIAN EMPIRE' 

 I. QAVES. — The cave of Vypustek, near Briinn, in Moravia, 

 was systematically explored, from April to end of October, 

 1S79, under the superintendence of the Committee, appointed 

 by the Imperial Academy of Sciences at Vienna, for Prehistoric 

 Investigations. The ossiferous layer, four to five metres thick, 

 and covered with a thin stalagmite, is a non-stratified breccia of 

 sand, loam, pebbles, and angular stones, with bones of "dilu- 

 vial " mammals abundantly, but irregularly, dispersed. Most of 

 the bones are fragmentary ; many of the pieces are rolled, and 

 even polished, by friction. Bones of Ursus spehcus predominate. 

 Eight to ten per cent, belong to thirty other mammalian species. 

 Some bones have evidently been gnawed by porcupines. In a 

 side cave, layers of charcoal and ashes, with fragments of 

 rudely-worked stone implements and bones of domestic animals, 

 showed it to have been once resorted to by human beings. 



The Kreuzberg Cave in Carniola has further enriched the 

 Academy's museum with numerous remains of Ursus spdtzus. 

 Skeletons of individuals of all ages lie together, but only in the 

 uppermost loam in the highest part of the cave. Thus the 

 animals inhabiting the cave may be supposed to have retired 

 before an irruption of water, and have perished by a flood in 

 in their place of retreat. In a side cave the stalagmitic floor 

 near the entrance contains some charred corn. 



A cave near Fiume, on the Adriatic coast, opened by railway- 

 works, appears to have been used as a burial-place in the stone 

 period, as human skeletons, bones of animals, stone implements, 

 and fragments of rude earthenware, were discovered in it. 



2. Tumuli— k tumulus opened in Lower Austria was found 

 to contain only a few worked stones, layers of charcoal, and 

 bones of animals. The skeleton of a woman, executed and 

 buried about seventy years ago, lay in its uppermost portion. 

 In the same province several low barrows were found to contain 

 stones placed in a circle, in the middle of which, on a stone 

 slab, lay the skeleton (not burnt), with many bronze weapons 

 and 'ornaments. Some larger barrows, probably of later date, 

 are reported to have contained urns and charred bones, a few- 

 objects of bronze and iron, and coins of Domitian. 



Of more than a hundred tumuli near St. Margareth, Lower 

 Carniola, twenty have been opened. A great many antiquities 

 were obtained : earthen vases of peculiar shape, articles in 

 bronze, iron, glass, and amber, and even gold ornaments. 



The tumuli near Jagnenza were found to contain skeletons 

 within elliptical rows of stones, and those near Unter-Erkenstein 

 had urns with burnt human bones. Another large barrow con- 

 tained a circle of stones, a human skeleton, burnt bones, char- 

 coal, iron objects, and bronze ornaments. 



NOTES FROM ITALY AND SICILY 



THE following notes, although necessarily of a desultory 

 character, may intere.-t some of our readers : — 

 Climate.— The climate of Southern Europe during the la>t 

 month, from the middle of December to January 20, has been 

 more severe than we ever remember it before. Long icicles 

 depended from the platform of the engine which conveyed us 

 1 Report of the Committee, &c, Imperial Academy of Vienna. Rep it f 

 Meeting, December 18, 1870. 



