10 



Increase in tlie weight of Motals durinjj coniliustion in 

 oxygen, by their chemical miion with the gas. The 

 complete combustion of a large file from a burning jet 

 of the mixed gasses, was effected during one of the ex- 

 periments occurring in this division of the subject. 



II. — On the conversion of Metals to Oxides by the de- 

 composition of some compound body in which oxygen is 

 present. 



Under this head was exhibited the decomposition of water 

 by red hot iron and the consequent formation of an oxide of 

 31etal, as well as the liberation of hydrogen gas from the 

 water. It was also shewn that a small proportion of Nitro- 

 gen is generally produced during processes of this descrip- 

 tion, and the existence of which in the present instance was 

 demonstrated by the proper tests. A variety of other expe- 

 riments tended to elucidate the principle upon which oxides 

 of the Metals obtain from the action of acids, water, &c. &c. 



III. — In entering this division of his subject, the lecturer 

 remarked that he should briefly direct the attention of the 

 audience to a very interesting and useful application of 

 chemical agency — the disengagement of oxygen from the 

 various oxides and their restoration to the metallic form. 



Among the experiments of this department we may notice 

 the reduction to the Metallic state of various oxides and pre- 

 parations of lead, iron, copper, and zinc, from the sub- 

 stances themselves and their sevei'al solutions — the reduction 

 of solutions of gold and silver to their pristine metallic state, 

 by the agency of hydrogen — the double allinity exhibited 

 by the contact of diflerent metals in the reduction of other 

 bodies of the same class from their combination with fluids 

 — the reduction of metals by galvanic action, &c. When 

 the lecturer took occasion to illustrate the utility of this 

 agent as a chemical test in detecting the existence of 

 poisonous preparations of the metals. The lecture concluded 

 by the introduction of a brilliant species of pyrophorus, pre- 

 pared extemporaneously from the tartrate of lead. 



November 24. — Mr. Warman delivered a Lecture on Ho- 

 rology, which he introduced with some opinions concerning the 

 Horology of the Ancients prior to the use of mechanical 

 time-keepers, and with remarks on their invention and history. 

 A minute description of the clock was given under four 

 heads. — 1st. The moving power, — the action of the weight 

 on the cj'linder and first wheel and the concomitant opera- 

 tions of the other wheels were shewn. 2nd. The re" ulatins; 

 power,— the method by which the gradual descent of the 

 weight is regulated by the swing wheel and vibrating pendu- 

 lum ; the delicate construction of the compensating pendulums 



