Proceedings of Learned Societies. 467 



Church then proceeded to describe the formation of travertine in 

 several localities in England, noting more especially the rapidity of the 

 process, the organic substances, occurring sometimes most abundantly, 

 in the deposits, and the physical characteristics of the formation. As 

 to this last point, the author pointed out the remarkable similarity 

 in construction between the discoidal concretions of carbonate of 

 lime in travertine and Harney's globular lime-crystals, pearls, and 

 the minerals pisolite and oolite. 



The latter portion of the paper was partly devoted to a brief 

 notice of the consolidation of various materials into rocky or mineral 

 substances by means of silica, oxide of iron, etc., and partly to the 

 peculiar processes by which certain mineral and metallic veins are 

 gradually formed by the elimination of the constituents from the 

 surrounding masses of mixed matters. Mr. Church noticed the 

 construction of the geodes of iron-ore, containing nuclei of ochre or 

 clay, found in the ochre pit on Shotover Hill, near Oxford ; the 

 formation still going on* of magnesiam limestone at the upper part of 

 Bullingdon Marsh, in the same neighbourhood ; the occurrence in 

 clay of calcareous concretions, and in chalk of silicious nodules ; 

 and the production, at the present time, in the chalk, of such 

 minerals as allophane and collyrite, in which forms much of the 

 silica and aluminaf of the chalk becomes, as it were, concentrated. 



In the interesting discussion which followed, Mr. Church sup- 

 ported his views of the modern formation of silicious minerals by 

 the case of the silicified basket of eg^s found in an abandoned chalk- 

 pit, near Winchester, many years ago. 



CHEMICAL SOCIETY.— December 18. 



Artificially Formed Alcohols. — A communication was read 

 from Professor Wurtz, in which he pointed out, among other novel 

 facts, certain hitherto unobserved differences between ordinary 

 alcohols as obtained by fermentation, and those artificially produced 

 by synthesis from the corresponding olefiant. The former may be 

 ■viewed as water in which one equivalent of hydrogen has been re- 

 placed by ethyle, or its homologues, the latter as water plus ethylene 

 or other olefiants. Ihis is shown by the formulae 



10 "R U l" ®' z Normal amylic alcohol. 



C 10 H 10 , H 2 2 Amylic alcohol formed by synthesis 



from amylene. 



Chinolinb Blue. — Dr. Hofmann gave a most interesting oral 

 account to the Society of his experiments on the constitution of 

 this beautiful but fugitive dye, discovered some years ago by 

 Greville Williams. A prize of 20,000 francs has been recently 

 offered in France to any one who will devise a way of rendering 

 this dye permanent, and the material is now manufactured on a 



* This modern deposit has been worked for magnesia commercially, 

 f Mr. Church displayed numerous illustrative specimens of the products 

 referred to, including crystals of sulphate of lime, and of sulphate of baryta, found 

 in septaria, in tiie London clay. 



