between concentric tubes closed b y melting o l e r the lamp, I found 16 cubic centinieters of decomposed carbonic acid. This gas attacked mercury and oxidizable bodies with extreme \ iolence. If the oxiciizing portion of this g n s i\ ozorie, the quaiititj vf this substance u a s 30 p. c. of the liberated oxygen in one case, arid, i l l anuther c‘use, 4 1 p. c. These yuantities are enormous conipareil t o those obtained with pure oxygen. “ I t would be very interesting to isolate t h e oxidizing substance formed in this reaction, but when we have tried to separate the carbonic acid and carbonic oxide of the preceding mixtimi, the oxidizing g a s ir destroye‘d by the reagents used for t h k separation. This g a s might be considered as oxygen strongly charged with ozone or with per-carbonic acid, C,O,, but I have not been able t o discover a n y properties b y which t o distinguish this last compound froni ozone mixed with carbonic acid.” On the Formcation of Ethers of H @ m c i d s iit the Griseous State, M.BERTHELOT. Researches on the Compressibility of Gases, M. L. CAILLEdescription of his new apparatus, and the results obtained with nitrogen.
TET.--A
11.1. MONOTpresented to t h e Academy specimens of ResztEts RecenXly Obtained in the Manufacture of various kinds of Crystal Glnss. ‘ b Aventurine is obtained b y reducing copper b y iron. “ T o obtain an imitation of the glass called vermeil, a glass of any kind is covered with a thin layer of glass charged with copper. T h e metallic surface is then obtained by a reducing gas. ‘ r h e metallic crackled glass is obtained b y using a crystal glass charged with oxide of silver. This is covered with some other glass of any color. B y taking off this glass in places, t h c silver glass is laid bare, and metallic effects are obtained b y a reducing flame.” i(
,Vew Com,poiand Prism, f o r Direct Vision Spectroscopes of great Dispersive Power, &I. THOLLOX. Note o n th.e Spectroscope of M . ThdZon, 31. LAURENT, Syntheses of
GRIYAU x.
Uric Derivcctes of the Alloxan Series, M. E.
