390 Additional Notes, 



Carlisle, Nicholson, Cruickshank, Haldane, Henrys aiid.mDre par- 

 ticularly to Mr. Dav}' and Dr. Wollaston. 



Me&srs. Carlisle and Nicholson did much towards establishing 

 the electricity of the pile, by ascertaining that it is minus in the 

 silver end, and plus in the zinc end. They also demonstrated its 

 chemical action^ especially in the decomposition of water j a 

 highly interesting experiment, which has led to many very im^ 

 portjnt results. 



Mr. Cruickshank was the first discoverer of the Galvanic pro- 

 duction of alkali. In his experiments he supposed ammoniac to 

 be generated j while, according to those of some others, the alkali 

 produced was thought to be fixed. He likewise invented the 

 mode of placing the metals horizontally in a kind of trough, 

 which, in several respects, is much more convenient than the ap- 

 paratus of Volta. And he was the first who succeeded in charg- 

 ing the Leyden phial by means of the Galvanic pile. 



jVIr. William Henry ascertained, by his experiments, that tlie 

 sulphuric and nitric acids may be decomposed by the operation 

 of the Galvanic influence ; but, in his attempts on the muriatic 

 acid, he only succeeded in decomposing the water adhering to it. 

 He also demonstrated that ap^imoniac may be decomposed in a 

 similar manner. 



Colonel Haldane found that the effects of the apparatus of 

 Volta were suspended when it was immersed in water -, and that 

 this likewise was tlip case when it was confined in azotic gas, or . 

 placed under the vacuum of an air-pump. He observed that the 

 pile acted more powerfully when immersed in a given quantity of 

 oxygen gas, than in the same bulk of atmospherical air. 



Dr. Wolla.ston has greatly contributed to enlarge our knowledge 

 of the nature and principles of Galvanism. He read an excellent 

 paper on this subject to the Royal Society, which appeared in 

 their Transactions iox i\\t year 1801. After stating a variety of 

 experiments most ingeniously devised, and cautiously as well as 

 accurately conducted, he advances his induction, from a great 

 number of distinct and luminous proofs, tliat the phenomena 

 of electricity and Galvanism are all results of the same principle. 



But scarcely to any one in Great Britain is Galvanism more in- 

 debted for its extension and improvement than to Mr. Davy, of 

 the Royal Institution, Aniong many piher discoveries of less im- 

 portaiice^ which die rapidity of this sketch dues not allow to be 

 mentioned, he first ascertained the fitness oi charcoal, when used 

 with silver, as a conductor of tlie Gidvanic infiuence. He dis- 



