Miscellanies. 197 



Bottles intended for the manufacture of brisk Champagne or Bur- 

 gundy, being tried, were found to break with a force between 12 

 and 15 atmospheres, exerted from within outwards: a few rose to 

 18 atmospheres. Bottles which had contained Champagne of the 

 finest quality, broke at the same pressures* Bottles which resisted 

 the pressure of 12 atmospheres, usually broke with one or two at- 

 mospheres more, but the number of these was small. The fracture 

 of bottles in the manufacture of brisk Champagne is from 10 to 20 

 per cent; and in certain cases, which, however, are rare, almost the 

 whole have been broken. It appears quite certain, that during the 

 fermentation of the wine, the pressure rises above 12 atmospheres, 

 but the full extent can be ascertained only by careful experiments 

 made by the wine proprietors. 



The commissioners then remark, that the best bottles intended for 

 brisk wines are too weak ; the general fault is want of strength and 

 uniformity in the belly of the bottle, especially at the junctions with 

 the neck and with the bottom. 



As the greater number of bottles for brisk wines are of the same 

 quality, it becomes a question why some should break and others 

 not. This difference is supposed to depend upon the form of the 

 neck and quality of the cork, allowing a little gas to escape in some 

 cases and not in others. If the bottles and corks were all alike, all 

 those which contained the same liquor at the same temperature would 

 probably break at the same pressure. The only means of avoiding 

 fractures is either to make the bottles sufficiently strong, or to allow 

 a little escape of gas by the cork. The least thickness of glass in 

 the belly of the bottle should be 2 millimetre (.079 of an inch,) 

 but generally it is only 1 millimetre at the part next to the bottom. 

 Bull. Univ. E. xiv. 80. 



3. Magnesium. Metal of Magnesia. — M. Bussy has stated at the 

 Academy of Sciences that he has been able to eliminate the base of 

 magnesia by a process similar to that practised by M. Wohler, and 

 he submitted a specimen for examination. 



Magnesium has a brilliant silvery white appearance ; is perfectly 

 malleable and ductile ; is fusible at a moderate temperature ; like 

 zinc, is volatile at a temperature somewhat higher, and may be con- 

 densed again into small globules. It does not decompose water at 

 common temperatures, but is oxidized in the air at high tempera- 

 tures when in small masses, and gradually forms magnesia. Its 



