507 



first, a complex internal shell, divisible into the same principal parts 

 as that of the Sepia, but one of which has, secondly, the same essen- 

 tial chambered structure as the shell of the Spirula ; thirdly, unci- 

 nated cephalic arms, as in the Onychoteutliis \ and lastly, an ad? 

 vanced position of rounded fins, as in the Spirula and JRossia. 



The paper is illustrated by drawings of the specimens described, 

 with microscopic views of the shell and muscular tissue, and a re- 

 storation of the Belemnite according to the data afforded by the pre- 

 sent fossils. 



April 18, 1844. 



The MARQUIS OF NORTHAMPTON, President, in the Chair. 



1. Note in addition to Mr. Gassiot's paper on the "Water Bat- 

 tery." The author here describes an instrument which he has re- 

 cently constructed, and by means of which he is enabled with great 

 facility, and without the aid of Zamboni's pile, to test the tension in 

 a single series of the voltaic battery. 



2. " On the production of Ozone by Chemical Means." By Pro- 

 fessor Shoenbein, in a letter to Michael Faraday, Esq., D.C.L., 

 F.R.S. Communicated by Dr. Faraday. 



The author conceives that of the two gaseous principles which 

 are simultaneously produced during the slow action of phosphorus 

 upon atmospheric air, and which have opposite voltaic characters, 

 that which exerts electro-positive properties is composed of vapo- 

 rized phosphorus, conjoined with particles of phosphatic acid ; and 

 the other, which is electro-negative, is identical with ozone, or the 

 odoriferous principle which is disengaged at the positive elec- 

 trode during the electrolysis of water. His opinion is founded on 

 the odour of the one not being distinguishable from that of the 

 other. 



3. "Contributions to Terrestrial Magnetism." No. VI. By Lieut.- 

 Colonel Sabine, R.A., F.R.S. 



This portion of the series consists of observations made on board 

 Her Majesty's ships Erebus and Terror, from June 1841 to August 

 1842, in the Antarctic Expedition under the command of Captain 

 Sir James Clark Ross, R.N., F.R.S. It comprises the result of the 

 operations conducted during the second year of the expedition, when 

 it proceeded early in July 1841, from Hobarton to Sydney, and 

 thence to the Bay of Islands in New Zealand, remaining there till 

 November, and reaching, in February 1842, in latitude 78°, the icy 

 barrier which had stopped their progress in the preceding year. 

 Quitting the antarctic circle in March, and keeping nearly in the 

 60th parallel, they crossed the whole breadth of the Southern 

 Pacific Ocean to the Falkland Islands, where they arrived in April 

 1842. 



On a general review of the magnetic declination in the southern 



