36 TiMEHRI. 



ments, to the process of extrafling sugar from the 

 cane ; for the simple reason that by its adoption 

 a purer juice in larger quantities, ought to be obtained 

 through its agency. Most processes for extracting the 

 juice from the cane have depended for success upon the 

 more or less complete rupture of the cells containing 

 the juice, as is the case when mills are used; and the 

 diffusion process differs from them essentially in dis- 

 pensing with sheer force and in endeavouring to substi- 

 tute the natural law of Osmosis, 



Allow me very briefly to explain the a6lion of " Diffu- 

 sion," " Osmosis," or " Dialysis.'' 



If a porcelain cylinder, open at both ends, be taken, 

 and parchment covers be firmly tied over these ends, and 

 the cylinder thus prepared be completety immersed in a 

 basin of circulating water, so that there can be no com- 

 munication between the water surrounding the cylinder 

 and the interior of the latter, save through the porous 

 parchment membranes ; and if into this jar with its 

 parchment covers, you have previously placed a dissolved 

 mixture of gum-arabic and sugar, it will be found in 

 due time that all the sugar will have diffused through the 

 parchment into the water surrounding the cylinder, the 

 gum at the same time being almost altogether left in the 

 jar. Thus, as with this experimental jar, so also with 

 the cane-slices in a Diffusion Fa6lory, we ought to be 

 able to procure from the canes a juice composed chiefly 

 of water and sugar, the more objectionable matters being 

 left behind in the exhausted slices. 



The constituents of sugar-cane-juice, and their propor- 

 tions, are well-known, and may be classed under two 

 distin6l groups : — (a) *' Crystalloids," including the sugar 



