in 1848 in the Botanic Garden at Florence, and at Padua in 1850, 1851, and 

 1852. In tlie whole series of his experiments, M. Zantedeschi always remarked 

 certain motions in plants having a delicate organization as soon as the}' were 

 brought under the influence of the lunar rays. In those experiments the rays 

 were always diffused, being neither concentrated by lens nor mirror. Such move- 

 ments could not be obtained by the action of heat, in whatever way thermal influ- 

 ences were applied. It was in vain to elevate or depress the temperature : in the 

 absence of moonlight the phenomena in question could not be elicited. The 

 plants on which M. Zantedeschi principally experimented were Mimosa ciliata. 

 Mimosa pudica, and Desmodium gyrans. He always took great care to deter- 

 mine exactly the position of the leafstalks and leaflets of the plants after they had 

 been exposed to the open air, and before they were directly illuminated by the 

 lunar rays. He thus avoided any causes of error which might have arisen from 

 the imperceptible motion of the air, or from a slight change of temperatui-e ; and 

 he satisfied himself fully that the effects observed did result entirely from the 

 action of the rays of light from the moon. Without entering into minute details, 

 it is sufficient to say that the results were ascertained when the temperature of the 

 air was 70° Fahr. ; and when Saussure's hygrometer indicated a medium state of 

 humidity. Under such conditions, the leafstalks of Mimosa ciliata were raised 

 half a centimetre, or about four-tenths of an inch; those of the Mimosa pudica 

 were raised one inch and two-tenths ; whilst the leaflets of Desmodium gyrans 

 exhibited distinct vibrations. It was thus demonstrated that moonlight has the 

 power, per se, of awakening the Sensitive Plant, and consequently that it pos- 

 sesses an influence of some kind on vegetation. It is true that the influence was 

 very feeble, compared with that of the sun ; but the action, such as it is, is left 

 beyond further question. This being so, the question remains ; what is the prac- 

 tical value of the fact ? It will immediately occur to the reader that possibly the 

 screens which are drawn down over hothouses at night, to prevent loss of heat 

 by radiation, may produce some unappreciated injury by cutting off the rays of 

 the moon, which Nature intended to fall upon plants as much as the rays of the 

 sun. 



"Even artificial light is not wholly powerless. De Candolle succeeded in 

 making Crocuses expand by lamp-light, and Dr. Winn, of Truro, has suggested 

 that the oxyhydrogen lamp may be made subservient to horticulture in the long 

 dark days of winter. It does not, however, appear that this hypothesis rests 

 upon any experimental basis." 



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