370 



a given measure of distilled water, the volume of distilled water equal 

 to the bulk of the body, the weight of the body when immersed in 

 distilled water, allowance being made for the difference between the 

 weight of the counterpoise in vacuo and in air. 



The chief difficulty is to procure a body of sufficient size not too 

 heavy for a delicate balance. It seems not improbable that a mate- 

 rial may be found which, when formed into a globe or a drum, and 

 filled with air merely for the sake of lightness, shall not exceed a 

 pound in weight, and yet may be of such a size as, with a balance 

 tui'ning with the tenth of a grain, may, under the occasional correc- 

 tion of exact methods, enable those who engage in meteorology merely 

 for the sake of occupation, to add to their register a near approxima- 

 tion to the daily density of air. If such a body, equal to or exceed- 

 ing a cubic foot in volume, cannot be provided with the requisite qua- 

 lities, namely, lightness, permanence in figure, impermeability to air 

 and moisture, and the being susceptible of having its expansions and 

 contractions, under changes of temperature, reduced to rule, a glass 

 globe capable of displacing 600 cubic inches of air, with a little more 

 pains and attention, can be made to serve the purpose recommended 

 in this communication. 



2. Researches on Chinoline and its Horaologues. By C. 

 Greville Williams. Communicated by Dr T. Anderson. 



In this inquiry, which is an extension of an investigation pub- 

 lished in the Transactions for last year, the author examines the 

 connection which has been said to exist between chinoline and qui- 

 nine, and shows that they bear no simple relation to each other. 

 He states, also, that the supposed analogy between the action of 

 heat on quinine and the hydrated oxide of tetramethyl-aramonium 

 does not exist, and that the assertions which have been made re- 

 garding the possibility of the formation of quinine from the leukol 

 of coal-tar ai-e founded on error. He then, after showing that chino- 

 line from cinchonine had not previously been obtained in a state of 

 pui'ity, gives the history and composition of the platinum, gold, and 

 palladium salts ; also the nitrate, bichromate, and binoxalate. 



He describes two new classes of salts formed by the chlorides of 

 cadmium and uranyl with organic bases, and gives the analysis of 



