1835.] the Advancement of Science. 201 



from coal gas in this, that the latter consists of double 

 defiant gas. 



The observations of Mr. Davy upon this subject corre- 

 sponded with those of Dr. Dalton. 



Wednesday^ August \2th. — 11. Mr. Mallet described the 

 phenomena presented in lamps, when the holes for the passage 

 of the gas are made as small as possible, and also the ap- 

 pearance observed when the direction of the tube is inclined 

 in different ways, two currents being formed when the tube 

 is inclined, and the surface of the flame presenting spiral 

 lines, and considerable retraction of the flame taking place, 

 none, however, occurring when the tube is not fully in- 

 serted. The apertures in the lamp were less than the ^J^ of 

 an inch in diameter. 



In the discussion which arose from this communica- 

 tion, Dr. Dalton observed, that 12 small holes in a lamp 

 consumed less gas and gave more heat than when the holes 

 were larger but fewer in number. But the great object in 

 procuring a proper quantity of heat depends upon the atmos- 

 pheric air being neither too great nor small in quantity. He 

 stated, that if we take a cubic inch of pure gas, and another 

 diluted with half its volume of air, each gives out the same 

 quantity of heat, but the latter scarcely yields any light. 

 This is an important fact, and deserves to be known. 



12. Mr. Connell read a paper in which it was his object to 

 point out some chemical facts, by which we maybe enabled 

 to detect, whether a fossil scale be that of a fish, orsauroid 

 animal, and illustrated his position by some analyses which 

 he had made on recent crocodile and fish scales, and upon 

 the scales found at Burdie House. His inference was, 

 that chemical analysis completely verified the idea of 

 Agassiz, that the scales found at Burdie House were those 

 of fish. He considers the animal matter to be replaced 

 by a little carbonate of lime and silica. 



13. Mr. Kane described two compounds of tin and plati- 

 num formed by the action of protochloride of tin upon a 

 solution of platinum. One of these compounds consists of 

 an atom of each chloride. It deliquesces in the air; is a 

 dark solid substance when anhydrous, and when allowed to 

 remain in the air is converted into an olive liquor, which is 

 resolved into the oxides by the action of water. The author 

 suggested that tin affords a good test for platinum. 



