Intelligence and Miscellaneous Articles. 63 



The great difficulty which has been experienced up to the present 

 time in the preparation of sugar, has been owing to the rapidity 

 with which it, when dissolved in water, alters by exposure to the 

 air in hot climates. It must, however, be clear, since the cells of 

 the sugar-cane are themselves full of sugar dissolved in water, and 

 this solution can be kept for a long time in them, without under- 

 going any alteration at all, that if the same conditions which exist 

 in nature could only be obtained in practice, there is no reason why 

 an artificial solution of sugar may not be kept unaltered for a con- 

 siderable space of time ; or in other words, why water should not 

 be used for the purpose of dissolving the sugar out of the crude juice 

 expressed from the cane. 



The difficulties, indeed, are not owing to the sugar or to the water, 

 but to the air, and the ferments produced by its action on the crude 

 sap of the sugar-cane. The object of M. Melsens was, then, to ex- 

 clude the air from the sap when extracted from the cane, and to 

 prevent the formation of any ferments which might change the cha- 

 racter of the saccharine matter. This he has succeeded in doing by 

 availing himself of the well-known affinity of sulphurous acid for 

 oxygen gas. Sulphurous acid, however, alone was found not to 

 answer the purpose ; the sulphuric acid, produced by the absorption 

 of oxygen by sulphurous acid, acting on the sugar, converts it into 

 grape-sugar. This difficulty has been overcome by using sulphurous 

 acid combined with a powerful base, which, as the sulphurous acid 

 is converted into sulphuric acid, combines with the latter and forms 

 an insoluble salt. 



The acid sulphites, and more especially the bisulphite of lime, 

 were employed by M. Melsens for the double purpose of preventing 

 fermentation by the action of the sulphurous acid, and of neutralising 

 the sulphuric acid as fast as it formed by means of the lime. 



Sugar-candy dissolved in cold water containing bisulphite of lime, 

 even in excess, crystallized entirely, and without undergoing any 

 change, by spontaneous evaporation, at a low temperature. Several 

 other experiments of the same nature, but differing in their details, 

 always gave the same result ; in each the sugar crystallized out by 

 spontaneous evaporation, without any loss either in quantity or in 

 quality, and without any appearance of molasses. In these experi- 

 ments, the sugar dissolved in water, containing bisulphite of lime in 

 excess, was boiled, and then left to evaporate, sometimes after being 

 filtered, sometimes without any filtration at all. 



From the experiments which M. Melsens has made with bisulphite 

 of lime, it is probable that if a cold solution of this salt were to be 

 poured on the sugar-cane grinder, so as to mix with the juice the 

 moment it is expressed from the cane, the sugar might be kept 

 for some time, and might be exposed to the heat necessary for its 

 clarification without any sensible loss or deterioration. 



But this same salt also possesses the property of coagulating, at a 

 temperature of 212°, milk, white of e^g, blood, and yolk of q^^ 

 mixed with water. At a temperature of 212°, bisulphite of lime acts 

 as a clarifier. It separates the albumen, caseum, and other similar 



