78; REPOUT 1861. 



and that he has also proved the nitrides formed to be decomposed by the hydrated 

 alkalies, ammonia being thereby generated, — it has occuiTed to the author that a 

 more probable explanation of the occurrence of ammonia in Tolcanos might be 

 afforded by supposing such combinations to take place in the interior of the earth, 

 and there to be subsequently decomposed by the alkalies which are usually present 

 wherever volcanic action is taking place. In confirmation of this view, he appealed 

 to a late observation made by Signer Guiscardi, a distingiiished naturalist at Naples, 

 namely, that metallic titanium was fovmd to be evolved from the crater of Vesuvius 

 during a late eruption. 



On a particular Decomposition of Ancient Glass, By H. Dbaite. 



The author's object was to show, first, that an inci-ustation obser\-ed within a glass 

 ampulla from the ancient Christian catacombs of Home was not organic matter, as 

 had been supposed ; and secondly, that it was the result of a decomposition of the 

 glass itself, probably originally coloiu-ed with peroxide of iron. This in the coiu'se 

 of time had separated, like the other ingredients of the glass, and found its way to 

 the surface in a spheroidal and arborescent form, similar to what may be observed 

 in moss agates. That it was not a mere extraneous deposit was obvious from the 

 fact of its being chiefly in the substance of the glass itselfj and nearly equally 

 disti'ibuted on both inner and outer smfaces. He had observed precisely the same 

 condition in some ancient glass from Nineveh, 



On Morin, and the non-eaistence of Morotannic acid. By Dr. Delffs, 



M. Wagner published in the year 1850 an investigation on the wood of 3Iorus 

 tinctoria, and stated that this wood contains two peculiar and isomeric matters, 

 morin and morotannic acid, the latter of which differs from all other tannic sub- 

 stances by being able to crystallize. Since that time no other chemist has discussed 

 the same subject. The author thought, therefore, a repeated investigation on morin 

 and morotannic acid would not be superfluous, and fx)und that morotannic acid is 

 only morin in an irapiu'e state, and that an often-iterated crystallization suffices to 

 convert it bito a white substance possessing all the properties of pure morin. The 

 composition of morin con-esponds to the foniiula C^^ IP 0'^ + 2 110. M. Wag-ner 

 gives the fommla C'lPO^". Moiiu most resembles catechin: it giyes, when 

 heated above its melting-point, pyi-ocatechic acid ; the colour produced in the sohi- 

 tion of catechin by chloride of iron is nearly identical with that which is caused 

 by the same test in the solution of impure morin ; and a comparison of the com- 

 position of catechin, which Dr. Delfl's fomid seventeen years ago (Jahrbuch fiir 

 praktische Phannacie, vol. xii. p. 162), and that of morin will show that the diflbr- 

 ence between both is not very great. The author tried, therefore, to convert 

 catechin by repeated ciystallizatiou into morin, but without result, and he is quite 

 convinced that these two substances are not identical. 



On Pijperic and Ilydropiperic Acids. By G. C. Foster, B.A., F.O.S. 



The analysis of piperic acid and of the piperates of potassium and barium led 

 to the formula C'- H'° 0'* for the acid, and to the formula C'- W MO' for the 

 salts ; thus confirming Strecker's formula) f- A. warm aqueous solution of piperate 

 of potassimn is converted, by treatment with sodium-amalgam, into hydropiperate 

 of potassium. Ilydropiperic acid melts to a transparent oil under hot water, and 

 dissolves in all proportions in alcohol : it contains C^^ II'- 0'. The following hy- 

 dropiperates were analysed : — 



Hydi'opiporate of ammonium C'^ H" (NIP) 0'. 



Acid hydropiperate of potassium. . p^^ rru irQi \ • 



Hydropiperate of calcium C'^ H'' CaO' (at 100°). 



Hydropiperate of barium C'^ H" BaO'. 



Hydropiperate of silver C'^ H'' AgO*. 



» C = 12, 11=1, 0=16. t Ann. Chem, Pharm. ct. 317. 



