CHEMICAL SCIENCE. 1*71 



rapid fermentation, and no gain can be derived from the operation. 

 But, by Melsens' process the difficulty and waste are obviated. With 

 water containing a small quantity of the bisulphite, not only may the 

 washing be effected with ease, but at the leisure of the planter. 

 Hours or days, at his will, may be employed in this operation, now, 

 perforce, neglected altogether. The saccharine washings will be 

 found nearly as rich in sugar as the juice proves, and if treated in the 

 same manner, by purification, by simple filtration, and by concentra- 

 tion in the free air to the consistency of syrup', crystallization will en- 

 sue with equal certainty and success, the product being in all re- 

 spects similar and equal to that obtained from the juice itself. 



" A comparison of the methods actually in use, in the extraction of 

 sugar from saccharine juices, with that prescribed by Melsens, will 

 assist in the formation of a correct appreciation of the superiority of 

 the latter. 



" By the present methods, the crushing being operated under ex- 

 posure to the air, the alterations attending it render rapidity of exe- 

 cution indispensable. But, however rapid the execution may be, it 

 does not, and cannot, prevent alterations from taking place. Again, 

 the purification effected by means of lime develops and stimulates 

 the formation of coloring matter, and compels the employment of ani- 

 mal black. Finally, the process of evaporation, which is effected at 

 a high temperature, modifies a portion of the sugar which the heat 

 renders uncrystallizable. From this results the necessity of resorting 

 to repeated operations, and to four or five successive crystallizations, 

 which are never completely productive. Melsens' method, on the 

 oilier hand, allows of ample time, dispenses with animal black, and 

 effects the production of the solid sugar by a single crystallization. 



" The present product of a hundred pounds' weight of sugar-cane 

 does not exceed nine pounds' weight of sugar, whereas the natural 

 contents are about eighteen, the whole of which may be extracted by 

 the new method. Introduced into this country, it will prove only 

 second in importance to Whitney's cotton-gin. It will increase the 

 culture of the cane and the manufacture of its precious secretion. 

 With the lessened cost of production, the price to the consumer must 

 also be lessened." 



Since the announcement of the discovery of Melsens in this coun- 

 try, the process has been repeated by various persons on the sugar 

 plantations of Louisiana with perfect success. Editors. 



THE DISCOVERY OF M. MELSENS. 



IN addition to the above description of M. Melsens' discovery, we 

 subjoin the following interesting statement, given by himself, of the 

 origin of the discovery and the confirmatory experiments undertaken 

 by him. After speaking of some previous investigations, he says, 

 " Three substances particularly fixed my attention : the binoxide of 

 azote, sulphurous acid, and aldehyde. This remarkable class of 

 compositions, having a great affinity for oxygen, and which contain 

 already two equivalents of this body, and absorb a third with facility 



