6S UEPORT — 1876. 



feathery bluish-black crystals. It is prepared by dissohang iodine in an alcoholic 

 solution of the methyl iodide. 



The ethyl iodide is analogous to the methyl iodide ; and the ethyl hydrate gives 

 a similar reaction with bromine and ammonia. 



The ethene bromide forms small hard prisms, which melt at about 270°. The 

 etheue chloride crystallizes from alcohol in needles. 



Picoline allyl compounds are all sirups, with exception of the platino-chloride. 

 The hydi-ate is more stable than the methyl, ethyl, or ethene h^ydrates, and after 

 evaporation at 100^ dissolves in alcohol with a brilliant purple colour, ^vhich may 

 be commimicated to silk. 



As picoline is not decomposed by potash in any form, it cannot be a nifrile or a 

 carbouine. It is not altered by being passed through a red-hot tube filled with 

 lime or lead peroxide. Boiling sulphuric acid and nitric acid, or a mixtm-o of both, 

 have no action on picoline ; but when the nitrate is heated it undergoes complete 

 decomposition into carbonic acid and probably water. 



Picoline probably does not contain a methyl group ; for on oxidation it yields 

 Dewar's pyridene dicarbonic acid. This acid is not derived from lutidine, as was 

 supposed by Wright. Experiments to prepare the aldehyde and alcohol fi-om 

 dicarbo-pyridenic acid lead to a prospect of success ; and from the alcohol true 

 methyl pyridine may possibly be obtained. 



On Ghtcinum, its Atomic Weujlit and Specijlc Heat. 

 By J. EiiEESoN Reynolds, M.D. 



On the Utilization of Sewage. By W. C. Silxak. 



On the Action of Hydriodic Add on mixed Ethers of the General Formula 

 C,^H2„+ 1-1-0 . CHg *. By R. D. Silva. 



On Sodium. By Anderson Smith. 



On the Manufacture of Iodine f. By Edward C. C. Stanford, F.CS. 



The author gives an interesting account of this manufacture, which in Great 

 Britain is confined to Glasgow and its neighbom-hood. He gives a resume of the 

 remarkable fluctuations in the price of iodine, and also of the changes in the uses 

 of kelp, or sea-weed ash, from its first manufacture about a hundi-ed years ago to 

 the present time. He traces its use from the beginning of the present century, 

 when it was the principal source of alkali, and when Scotland alone produced 

 20,000 tons annually, worth £20 to £22 per ton. During the following 22 years 

 the importation of barilla reduced the price of kelp to £10 per ton. Then the 

 removal of the duty on barilla, followed by that on salt, reduced it further to £3 

 per ton, and in 1831 to even £2 per ton. In 1845 the manufacture of iodine com- 

 menced, and kelp was again in demand. The imports and prices are shown in the 

 following table (p. 69). 



It was impossible to give the imports of kelp earlier than 1845, as this table was 

 obtained with difficulty from indirect sources, the Clyde trust having disposed of 

 their books previous to 1859, thus rendering the early history of this interesting 

 subject at present inaccessible for statistics. 



It is shown that a large number of makers of iodine in Glasgow at that time had 

 been now reduced to three, 



* Vide Compt. Bend. kxxi. pp. 323-325. 



t Published i)i e.rfenso in the ' Chemical News,' 1877. 



