194 



and also with a water battery belonging to Professor Daniell, con- 

 sisting of 1020 series : but when a Leyden battery of nine jars was 

 introduced into the circuit of the latter, sparks passed to the extent, 

 in one instance, of six five-thousandths of an inch. 



The author mentions his having been present at the experiment 

 of Professor Daniell on the 16th of February, 1839, when that gen- 

 tleman had 70 series of his large constant battery in action ; and 

 having been witness of the powerful effects obtained by this appa- 

 ratus, he was induced to prepare 100 series of precisely the same 

 dimensions, and similarly excited : but although this powerful appa- 

 ratus was used under every advantage, and the other effects pro- 

 duced were in every respect in accordance with the extent of the 

 elements employed, still no spark could be obtained until the circuit 

 was completed ; even a single fold of a sdk handkerchief, or a piece 

 of dry tissue paper, was suflicient to insulate the power of a battery, 

 which, after the circuit had been once completed, fused titanium, 

 and heated 16 feet 4 inches of Xo. 20 platinum wire. 



The author then describes a series of experiments made with in- 

 duced currents. Twelve hundred and twenty iron wires, each insu- 

 lated by resin, were bent mto the form of a horse-shoe. A primaiy 

 wire of 115 feet and a secondary of 2268 feet, were wound round 

 the iron wires. With this arrangement he obtained a direct spark 

 (through the secondary current), sufficient to pierce paper, to charge 

 a Leyden jar, ozq. Several forms of apparatus employed by the 

 author are next described, and also a series of 10,000 of Jacubone's 

 piles. With this arrangement he charged a Leyden battery to a 

 considerable degree of intensity, and obtained direct sparks of tlu'ee- 

 fiffcieths of an inch in length. He ultimately succeeded in obtaining 

 chemical decompositions of a solution of iodine and potassium, 

 the iodine appearing at the end composed of the black oxide of 

 manganese. 



The Society then adjourned over the Christmas Vacation, to 

 meet again on the 9th of Januaiy, 1840. 



January 9, 1840. 



JOHN WILLLIM LUBBOCK, Esq., V.P. and Treasurer, in the 



Chair. 



John Augustus Lloyd, Esq., who, at the last Anniversaiy, had 

 ceased to be a Fellow, from the non-payment of his annual contri- 

 bution, was at this meeting re-admitted by ballot into the Society, 

 agreeably to the provision of the Statutes, 



James Whatman, Jun., Esq., M.A., was balloted for, and duly 

 elected into the Society. 



