808 REPORT— 1898. 



slightly greater in the case of slate, and about 3 jier cent, in the case of a 

 rather soft sandstone. 



3. On the Determination of the Thermal Conductivity of Water. 

 By S. R. MiLNER, B.Sc, and Professor A. P. Chattock. 



This is a description of a modification of the method of Ur. C. H. Lees, in 

 which the same platinum coils are used both for providing the flow of heat and 

 for measuring the resulting temperature gradient. The result obtained by taking 

 the mean of about forty separate determinations is 0'00I435 eg s. units at 20°C. 



4. Experiments on the Influence of Electricity on Plants. 

 By Sklim Lemstrom. 



A brief sketch is given of previous experiments and theories founded thereon. 

 The author has taken up the subject again for the following reasons: — 



(a) In previous experiments there was nearly always a favourable result when 

 artihcial electricity was used. The extraordinary development of the vegetatioik 

 in northern regions, in spite of the hard climatic circumstances. Periodicity in the 

 crops of difterent seeds, which follows closely the periodicity of the sun-spots and 

 the auroras, at least in more northern countries. 



{b) The same periodicity in the development of the annual rings in the pioe- 

 wood. 



(c) The unexplained physiological functions of the needle-formed leaves of the 

 pine and of the brush on the ears of the seed. 



After having found, and as nearly as possible proved, that the auroras are caused 

 by electric currents in the atmosphere, the author began a long series of experi- 

 ments, using a current of static electricity from points : 



1. In the laboratory with various seeds ; 



2. In Wichtis parish in Finland on a small cornfield ; 



3. On the field of the Horticultural Society in Helsingfors and on a wheat- 

 field in the Estate Brodtorp. 



As all these experiments, performed in 188.5 and 188G, had given favourable 

 results, about 40 per cent, increase of the plants treated with electricity, the author 

 made the necessary preparations for more extensive experiments in the year 1897. 

 They were carried out on the Estate Biodtorp, with the friendly assistance of 

 the proprietor, Baron Edvard Hisinger. 



Three fields of 50 m. were iised for the experiments, and three of the same area, 

 as control-fields. 



The results were the following : — 



There has been in general an increase in the seeds of at least 40 per cent. ; in 

 the roots from 25 per cent, to 75 per cent , dependingon the kind of plant and on the 

 nature of the soil ; beans, 75 per cent. ; strawberries and raspberries as high as- 

 75 per cent., and the time for their ripening shortened at least one-tliird. 



From these experiments it follows : — ■ 



1 . The more fertile the soil the greater the increase ; 



2. Some plants were improved b}' electricity, whilst others, »uch as carrots^ 

 behaved diflerently. 



Later experiments, however, have shown that this peculiarity depended on 

 want of water. It seems that under the influence of electricity the plants absorb 

 water in greater quantity. 



In the year 1888 the experiments were made near the Castle Laferte, in Bour- 

 gogne, through the kindness of Baron Arnould Tlienard. 



The results were in general the same as in Finland, though the weather during 

 the summer of 1888 was not favourable. 



Among the facts which result from these experiments it is proved that elec- 



