Chemical Science. 165 



gave an aqueous solution which evaporated to dryness, and freed 

 from resin and extract by alcohol, left a peculiar yellow colouring 

 matter, soluble in water, and combining with various bases. When 

 incinerated, civet gave a voluminous coal, alkaline, and containing 

 carbonate and sulphate of potash, phosphate of lime, and oxide of 

 iron. Hence civet appears to contain, free ammonia, stearine, 

 elaine, mucus, resin, volatile oil, yellow colouring substance, 

 salts, 8^c. No benzoic acid could be found in it. — Jour, de Phar. 

 1824. p. 537. 



24. Composition of Common and Deoxidized Iiidigo. — Mr. Dal- 

 ton, in a paper published in the Mancfiester Memoirs^ states, that in 

 various experiments made at different times, but with very similar 

 results, he finds that the quantity of oxygen required to convert the 

 green or deoxidized indigo solutions in lime water into blue indigo 

 is about \ or -^ of the weight of the resulting indigo ; and on the 

 supposition that an atom of oxygen was added to one of indigo, 

 concluded tliat the atom of indigo must weigh about 55 or 5ff. 

 When indigo is destroyed by the oxymuriate, or rather, chloride 

 of lime, as in the process adopted by Mr. Dalton for testing the 

 value of indigo, he is persuaded from his experiments, that twice 

 the quantity of oxygen is necessary that is required to revive it 

 from the lime solution. 



25. Decolouring power of different substances. — From certain 

 experiments made by M. Payen on the decolouring power of various 

 carbonized, mineral and other substances, it results that the schists 

 of Mermat in Auvergne, and the carbon of calcined bones decolour 

 in the highest degree. The schist removed f of the colouring^ 

 matter, the carbon f . — Ann. de Chim. xxvii. 360. 



26. Prize questions. — By the Royal Academy ot Sciences of 

 Toulouse, for 182G, "A physico-mathematical theory of lifting 

 and forcing pumps, demonstrating the ratio between the moving 

 power employed and the quantity of water raised, the height to 

 which it is raised being known, and all the obstructions which tlie 

 force would have to overcome being considered." The prize a 

 gold medal of 1000 francs value. 



For 1827 "The manner in which the known anti-feraientative 

 and anti-putrescent re-agents, such as camphor, garlic, peroxide, 

 and perchloride of mercury, sulphurous acid gas, c^c, oppose the 

 spontaneous decomposition of vegetable and animal substances, 

 and thus prevent the formation of alcohol in the former, and de- 

 velopement of ammonia in the latter." A medal 500 francs iu 

 value. 



