40 REPORT — 1875. 



I. 0-2044 grm. of sutstanee yielded 0-1517 H, O and 0-4425 CO^. 



II. 0-2039 grm. of substance yielded 01504 H^ and 0-4412 CO^. 



CH, Theory. Pound. 



I. n. 



A 



CH— CH— i 



C,H, (C= 59-02 59-04 6901 



=C,,H^„0.= ■^H= 819 8-24 8-19 



COOC, H, 0= 32-79 32-72 32-80 



COOO.H, 100-00 100 00 10000 



^2 ■^'^S 



The new ether is a colourless liquid of peculiar unpleasant smell ; its boiling- 

 point is about 262° C. ; as indicated by theory, it acts readily upon sodium with 

 evolution of hydrogen. 



The further study of the properties of this ether and of its isomer derived from 

 isobutyric acid, and more especially their decomposition under the influence of 

 alkaline hydrates, are already under investigation. 



The Tobacco Trade of Bristol. By Thomas Davey. 



A simple Method of determining the Proportion of Carbonic Acid in Air. 



By A. S. Davis. 



On the Chemical Theory of Gunpowder, By Dr. Debus, F.JR.S. 



The author stated that ever since the introduction of gunpowder this subject has 

 received considerable attention from chemists. The French chemist Gay-Lussac 

 was the first to make a systematic analysis of the products of combustion ; but it 

 was not possible satisfactorily to explain the reactions taking place by a formula. 

 The researches of Professor Bunsen and Schischkoff have shown that a much larger 

 number of products is formed than was previously supposed, rendering it even more 

 difficult to explain the nature of the changes taking place by a symbolic formula. 

 Professor Bunsen, of Heidelberg, found, by the combustion of a mixture of hydrogen 

 and carbonic oxide with a quantity of oxygen not sufficient to bm-n the whole of 

 the two gases, that the water and carbonic acid produced stood to each other in 

 proportion of their molecular weights, or then- molecular weights multiplied by 

 simple coefficients ; and these coefficients may be the same for mixtures of various 

 compositions, but change suddenly when the amount of one or both of the gases is 

 changed beyond certain limits. The author has shown that the same law obtains 

 when a mixture of bai-ic and calcic chloride is precipitated by an insufficient amount 

 of sodic carbonate, viz. that the barium carbonate and calcium carbonate precipi- 

 tated are in proportion of their molecular weights, or their molecular weights 

 multiplied by a simple coefficient. A necessary condition is that the reactions 

 should be simultaneous. In the combustion of powder in an ordinary gun this 

 condition is very nearly satisfied, and accordingly the quantities of some of the 

 products formed obey the law enunciated by Bunsen. The author deduced from 

 -the analytical results published in Messrs. Noble and Abel's most excellent 

 researches on fired gimpowder, as well as from the analyses of the products of the 

 combustion of powder published by Bunsen and Schischkoff, the following general 

 results concernmg the products of combustion : — (1) the sum of the potassium con- 

 tained in the potassic hyposulphite, sulphate, and sulphide stands to the potassium 

 in the potassium carbonate approximately in simple proportions ; (2) the carbon of 

 the carbonic oxide stands to the carbon of the potassic carbonate also approximately 

 in a simple proportion. From this, as well as from the relation of the sum of the 

 potassiimi contained in the sulphide and hyposulphite to the potassium in the sul- 

 phate, it is possible to foi-m a theory for the combustion of powder. There are 

 several reactions between the constituents of powder when the latter is fired. Two 



