170 ANNUAL OF SCIENTIFIC DISCOVERY. 



preventing the alterations occasioned by the presence of the latter in 

 the juice. 3. As a purifying agent, which, at 100 degrees, will clari- 

 fy the juice and separate from it all albuminous and coagulating sub- 

 stances. 4. As an agent capable of expelling preexisting colors. 5. 

 As an anti-colorant, capable of effectually preventing the formation of 

 coloring matter. 6. As an agent capable of neutralizing the injurious 

 acids which may be found existing, or may be engendered in the manu- 

 facture. 



"The questions that next presented themselves for investigation 

 were, in what proportions, and under what forms, the bisulphite of lime 

 should be applied, what inconveniences, balancing its promised ad- 

 vantages, might attend its use. To enable himself to answer these 

 questions satisfactorily, Melsens procured from the province of Murcia, 

 in Spain, where for ages sugar from the cane has been manu- 

 factured, a quantity of ripe canes. They reached Paris in good 

 condition, and were deposited in the laboratory of the Sorbonne, where 

 the experiments were being prosecuted. A number of persons con- 

 versant with the manufacture of sugar in the colonies were pres- 

 ent at the first essays. The results were such as to fill them with 

 surprise. The juice was extracted by crushing the cane in a com- 

 mon mortar previously supplied with the bisulphite. It was puri- 

 fied by ebullition, and then passed through a piece of cloth. The 

 syrup, after being concentrated and filtered a second time, was left to 

 slow crystallization. The sugar obtained by this simple process was 

 as excellent in quality as could have been obtained by the use of 

 alcohol. 



" The experiments tried in Paris upon the cane-juice demonstrate 

 that the employment of the bisulphite secures the extraction of all the 

 sugar contained in the cane, and produces it in a solid and crystallized 

 form. The crystals are large and firm : they are not more colored than 

 common candy, of which they have the appearance, and they exhibit 

 no appreciable traces of the slightest alteration being effected in the 

 saccharine properties. If, therefore, we take into consideration the 

 almost absolute purity of the cane-juice, which is in reality nothing 

 but sugared water, when purification has once been effected, and if we 

 also take into consideration the special aptitude of cane-sugar to as- 

 sume the form of large crystals, it would seem almost certain that the 

 first planter who will submit a quantity of syrup to slow crystallization, 

 by Melsens' method, will obtain crystals exceeding in size and quan- 

 tity, and excelling in whiteness and appearance, all previous expe- 

 rience. 



" But we have not done with the advantages that will attend the 

 introduction of this new agent. It is well known that the juice ex- 

 tracted from the cane by means of pressure is but a small proportion 

 sometimes only a half, and at most two-thirds of what might 

 be extracted. There remains, therefore, behind, a third or more of 

 the natural yield of the sugar-crop, and this third becomes, we be- 

 lieve, a total loss. The extraction of the sugar, thus wasted, by sim- 

 ply washing with pure water, is not to be thought of. The air, the 

 heat, the fermentatives, and other causes, contribute to establish a 



