NOTES AND ABSTRACTS. 



259 



differences in electrical potential of the atmosphere upon the growth of 

 plants. The plants experimented with were grown in glass cases, kept 

 in a greenhouse, the air of which was found at no time to indicate any 

 electrical potential. All conditions of culture were kept as nearly as 

 possible identical in the cases, except that half the cases were charged 

 each morning to a potential as near 150 volts as possible by means of a 

 wire projecting into the case from a Topler-Holtz influence machine, 

 the electrical measurements being made by a Thomson quadrant electro- 

 meter. The cases were all kept closed for four hours after charging, 

 then opened, so that for twenty out of the twenty-four hours the plants 

 were all under identical conditions. The result showed an average weight 

 as follows : — 



Exp. 1. Exp. 2. 



Tops Roots Tops Roots 



Normal case .... 10-097 2-33B -669 -724 

 Electrically charged case . . 15-7o0 3-8o0 -990 1-072 



radishes being the plants experimented with. The leaves were at times 

 carefully measured, and it was found that in every case the width and 

 length of the leaf-blade, and the length of the petioles of the plants 

 electrically treated, exceeded those of the normally grown plants ; although 

 these were not increased proportionately they were also of a lighter 

 green colour, and appeared more succulent, although moisture determina- 

 tions made at the end of the experiment did not show a difference in 

 this respect. The leaves of the electrically treated plants showed a greater 

 tendency to leaf-burn than did the normal plants. The author considers 

 that these experiments indicate that static charges act as more pronounced 

 stimuli than current electricity when applied to soils. 



Another series of experiments was started to ascertain whether 

 trees modify the electrical potential of the air in their vicinity to any 

 extent, and it is concluded that they do, at least when in foliage, 

 probably serving to keep the potential of the earth and air in more or 

 less equilibrium. It appears possible, however, that all trees do not 

 conduct electricity in the same direction. It is thought likely that the 

 detrimental influence of large trees upon crops and vegetation generally 

 in their vicinity is not wholly to be accounted for by the lack of sunshine 

 and soil moisture, but is in part due to the influence of trees in con- 

 ducting electricity. — F. J. C. 



Eremupi, The. By W. J. {Garden, No. 1786, p. 85 ; February 10, 

 1906). — Eremuri start into growth early in the year, and the tips of the 

 leaves as well as the flower-spikes are frequently cut back by the late spring 

 frosts, spoiling the latter for the season. It is therefore advisable to plant 

 them between low-growing shrubs, where they may obtain the necessary 

 shelter, or else shelter should be provided in the shape of ashes or inverted 

 pots until danger of frost is over. When planted between shrubs in this way, 

 as the soil soon gets exhausted by the roots of the latter, it is necessary 

 to replant every two or three years. This work may be performed as soon 

 as the leaves have died down, lifting the plants carefully, removing the 

 soil to a depth of 2 feet, then filling the holes with a mixture of good 

 fibrous loam, leaf -mould, and sand. Plant the roots so that the crowns 

 are about 6 inches below the surface of the ground, using plenty of sharp 



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