IS 



brandies, ami loaves, it becomes subject to the influence of 

 light and air. Drawings of the conducting and returning 

 vessels were exhibited. The various diseases arising from 

 the obstruction or diversion of the sap were explained ; 

 and some remarks were offered in conclusion on the degrees 

 of sensation and excitability apparent in some of the pro- 

 ductions of the vegetable world. 



May 5. — Mr. W. H. Weekes delivered a Lecture on the 

 Metallic Ores, the Metals, and their Oxides. In com- 

 mencing this series the lecturer remarked, that he felt to a 

 certain degree he was about to risk the consequences of an 

 experiment upon the taste, judgment, and good opinion of 

 his auditors, as he should have to render their lecture-room 

 subservient to the purposes of the laboratory, and devote 

 the table to the support of crucibles, blast furnaces, and 

 other apparatus suited to the analysis of organic bodies. 

 After an introduction illustrative of the general nature of 

 that class of bodies, the examination of which he was about 

 to undertake, and conveying to his audience an outline of 

 the modes pursued in smelting or reducing the ores of the 

 metals upon a large scale, shewing also experimentally the 

 most easy and direct methods by which they may be assayed 

 for the purposes of philosophical inquiry, Mr. W. introduced, 

 from the mineral cases of the Museum, a specimen of native 

 sulphuret of antimony, and exemplified by numerous mani- 

 pulations how it might be successfully analysed, both in the 

 dry and humid way, until he at length separated the whole 

 of its components — sulphur, lead, iron, silver, &c. and exhi- 

 bited the antimony, in a beautifully arborescent metallic 

 form, floating upon the surface of a jar of water. The 

 whole of the experiments, and the principal apparatus em- 

 ployed this evening, presented to the audience a novel 

 feature, and among the latter appeared a blowing machine 

 upon a new principle, portable in its construction and de- 

 cidedly effective in supplying the operator's blast furnaces 

 with a constant stream of atmospheric air. The inexhausti- 

 bility of this department of chemical inquiry, seems to be 

 indicated by the circumstance of the lecturer having oc- 

 cupied the attention of the society during one evening by 

 his operations upon a single specimen. After the lecture 

 Mr. W. introduced a singular and interesting form of expe- 

 riment, shewing the complete reduction of nitrate of silver 

 from its aqueous solution, andits tendency, when placed in the 

 plane of the magnetic meridian, or within the influence of a 

 powerful magnet, topassin the direction of the magnetic poles. 



