108 CJironieles of Science. [Jan., 



the sugar remained exposed to the bleaching action for forty-eight 

 hours. This process gives excellent results with the strongly- 

 coloured West Indian sugars ; with samples less coloui-ed the action 

 is not so marked. In the first case, two-thirds or three-fourths of 

 the colouring matter is completely removed. 



M. Dumesnil has devised a new process for preserving wine, 

 which is of considerable interest. The cask of wine, uncorked, 

 is placed under an iron bell and the air exhausted ; two hours' work 

 is necessary before the noise occasioned by the exit of the air ceases. 

 A vacuum being created, the gases contained in the wine are 

 released from atmospheric pressure and expand sufiiciently to break 

 the cells of vegetable fibrin enclosing them, and escape. The 

 withdrawal of 30 or 40 htres of gas occasions no sensible decrease 

 of hquid. M. Dumesnil gives an example of the practical value of 

 his process. He allowed the wines of 1865 to ferment till March,' 



1866, so as to allow of the conversion of all the sugar and extractive 

 matter into alcohol. At this period he substituted for the usual 

 operations the treatment by the vacuum ; fermentation ceased 

 entirely. The wines thus treated arrived at their destination in 

 good condition ; with other samples treated in the usual way the 

 result was very difierent. Notwithstanding fom* rackings, and 

 possibly four clarifications, the wines have continued to ferment 

 during the whole of the year 1866 and also the commencement of 



1867, and they probably still contain gases which will aftect them 

 more slowly. M. Dumesnil mentions that his wines of 1867, 

 treated in last March by the vacuum, yielded twice as much gas as 

 those of 1865. 



A memoir presented to the Academy comprises the first portion 

 of the results of M. Kolbe on the bleaching of flax. The research 

 has led to the establishment of the follo\^^ng facts : — The gummy 

 substance which adheres to the fibres of flax is nothing else than 

 pectose. The soaking or steeping of the fibre appears to have for 

 its object the determination of the poetic fermentation, and the 

 pectic acid which results remains fixed on the flax, either mechani- 

 cally or, in part, in the form of pectate of ammonia. The caustic 

 alkalies in the cold form gelatinous pectates, which preserve the 

 fibre from being completely attacketl. Pectic acid being w(^ak, 

 the alkahne carbonates have in the cold only a feeble action upon 

 the fibre. Ebulhtion, on the contrary, transforms pectic acid into 

 an energetic acid — metajiectic acid ; the carbonates are then strongly 

 attacked, and their employment becomes as eflicacious as that of 

 caustic alkalies. The carbonate of soda, even in lai-ge quantity, 

 is not a cause of the weakening of the fibre, which loses more 

 strength from the employment of caustic soda, especially when the 

 lye is concentrated. The employment of lunc, even in the cold, 

 weakens the fibre considerably, but the chief cause of the destruction 



