208 Analysis of the Chinese Gong. [Sept. 



insoluble in alcohol contains a distinguishable quantity of phos- 

 phate of soda, a little of a similar animal matter to that found in 

 the secretions, and also the earthy phosphates which were held in 

 solution by the lactic acid, and were precipitated by the action 

 of the alcohol. The urine possesses also a number of other 

 substances, which will be specified when describing this excre- 

 tion in particular. 



Having thus given some general views of the composition of 

 all the secreted fluids, I shall proceed to give a short account of 

 each individually. 



(To be continued.) 



Article VII. 



Analysis of the Chinese Gong. By Thomas Thomson, M.D. F. R. S. 



The Chinese onng is an instrument that has been long known 

 in this country) though I am not aware of any account of its 

 constituents having been hitherto published. My friend Dr. Reid 

 Clanny, of Sunderland, having some time ago sent me a speci- 

 men of this metal, with a request that I would ascertain its 

 composition, I thought it might gratify my readers if I stated 

 the result of my trials in the Annals of Philosophy. 



The Chinese s,ong is a large circular instrument, somewhat 

 similar in shape to a tambourine, excepting that it is entirely of 

 metal, and that the face is not flat, like the face of a tambou- 

 rine, but somewhat convex. The metal of which it is composed 

 has exactly the appearance of bronze. It varies in thickness in 

 different parts, from the -jMh to the -^th f an inch in thick- 

 ness. The surface is irregular, and bears evident marks of the 

 hammer; yet the metal is brittle, and very elastic. When 

 broken it has a granular texture, and its colour is rather whiter 

 than any part of the surface exposed by means of a file. 



This brittleness of the gong, although it had obviously been 

 made under the hammer, naturally suggested the idea that it 

 would be found malleable at some temperature between that of 

 the atmosphere and a red heat ; and I was going to undertake a 

 course of trials in order to determine the point : but Dr. Wol- 

 laston informed me that he had already made the experiment, 

 and found the gong quite malleable at a temperature considerably 

 below that of a red heat. He had been induced to undertake 

 his experiments in consequence of a gong belonging to Sir 

 Joseph Banks having cracked. Dr. Wollaston determined the 

 composition of the metal, made a quantity of similar alloy, 



