462 Proceedings of the 



been evaporated to dryness and exposed to air for some time, when 

 re-dissolved, and converted by nitric acid into a nitrate, and then 

 tested by nitrate of silver, gave so small a quantity of chloride of 

 silver, as evidently to show that the chlorine had never so far acted 

 upon the alkali as to produce any sensible portion of chloride or 

 chlorate, but had been almost entirely set free again as uncombined 

 chlorine. 



The necessity of attending very nicely to the preparation of the 

 substances when they were intended for medical uses, was insisted 

 upon, according to M. Labarraque's directions ; but when required 

 for common domestic uses, which must daily become more numerous, 

 the ordinary bleaching powder, or a common soda preparation, were 

 recommended as being quite as effectual and more economical. 



Later in the evening, the Mummy of a Cat, presented to the 

 Museum by Mr. Leverton, was opened upon the lecture-table by 

 Dr. Granville, who directed the attention of the audience to the 

 manner in which the bandages were applied and the limbs folded, 

 and to other interesting points which arose during the examination. 



In the Library were three Kaleidophones, an instrument, the 

 invention of Mr. Wheatstone, for a description of which, see page 

 344 of the present number. 



On the tables were numerous specimens of antient and modern 

 literary works. 



Friday y May llth. 



On this evening, Mr. Brockenden offered some remarks upon 

 the Tenacity of Metals, and a new mode of Wire-drawing. He, 

 some years since, patented an invention for drawing fine wire 

 through holes pierced in gems, which, for wire of a valuable mate- 

 rial, has been completely successful. Pierced gems are now gene- 

 rally used by the manufacturers of gold, silver, and gilt wire, at 

 Lyons in France, and in England. The advantages of using the 

 holes made in gems, instead of those formerly pierced in metal-plates, 

 are numerous and important. From the perfect lustre which is given 

 to the hole by the diamond-powder used in polishing and finishing, 

 it never removes the gold from the silver and copper-gilt wires, 

 but imparts to the metal a peculiar brilliancy. The durability of 

 the holes is so great, that a piece of wire, 800 miles in length, has 

 been drawn through a hole pierced in a ruby -^^-^ of an inch 

 diameter, without any measurable variation in the size of the ends. 



