1880.] 



Presents. 



2D5 



In reply to the questions that have been frequently asked regarding 

 the cost of maintaining an experimental electric light of 1,400 candle- 

 power, such as I have used in these experiments, I may state that the 

 3 horse-power Otto gas engine employed in driving the dynamo- 

 machine, consumes nearly 900 cubic feet of gas during the night of 

 12 hours, or 75 cubic feet an hour (including 7 cubic feet of gas 

 employed by the igniting burner) which, at 3.?. 6cl. per 1,000 cubic 

 feet, represents a cost of a little over 3d an hour, or with the carbons 

 6d. an hour. This, however, does not include superintendence or 

 incidental expenses, the amount of which must depend upon the 

 circumstances of each case.* 



The Society then adjourned over the Easter Recess to Thursday, 

 April 8th, at half-past four in the afternoon. 



Presents, March 4, 1880. 



Transactions. 



Geneva : — Societe de Physique. Memoires. Tome XXYI. 2 e Partie. 



4to. Geneve 1879. The Society. 



London : — Anthropological Institute. Journal. Vol. IX. No. 2. 



8vo. London 1879. The Institute. 



Clinical Society. General Index to the First Twelve Vols, of the 



Transactions, 8vo. London 1880. The Society. 



Corporation of London. Catalogue of the Library. Fifteenth 



Supplement. 8vo. London 1879. 1 The Corporation. 



Geological Society. Quarterly Journal. Vol. XXXVI. Part 1. 8vo. 



London 1880. The Society. 



Pharmaceutical Society. Calendar. 8vo. London 1880. 



The Society. 



Royal Astronomical Society. Memoirs. Vol. XLI. 4to. London 

 1879. The Society. 



Royal Microscopical Society. Journal. Vol. III. No. 1. 8vo. 

 London 1880. . The Society. 



Pesth: — Magyar Tudomanyos Akademia. Almanach. 1879-1880. 

 8vo. Budapest 1879-80. Ertesito 1878. Nos. 1-7. 1879. 

 Nos. 1-6. 8vo. Budapest 1878-9. Archeeologiai Ertesito. 8vo. 

 Budapest 1878. Evkonyek. XVI. Nos. 2-5. 4to. Budapest 

 1878-9. Kozlemenyek Archseologiai. XII, XIII, No. 1. 4to. 



* Since sending in my paper to the Royal ^Society my attention has been drawn 

 to some experiments made in 1861 by M. Herve-Mangon, who proved that by means 

 of the electric light, chlorophyll was developed in young plants of rye. 



