DEFECATIOX WITH LDIE. 293 



brownish-red, and the bhie litmus to a j)urple or red, according as the 

 lime present is in less or greater excess. 



The visible effect produced by adding the lime will be the formation 

 of a precipitate throughout the liquid, which was before comparatively 

 clear. This cloudy precipitate will be seen to gather itself in flocks, 

 and these will either slowly settle to the bottom or rise to the top of 

 the mass of juice, leaving at last the intermediate portion quite clear. 

 It will also be observed, that the green color of the juice will change 

 to a yellow (brownish-yellow), leaving the juice, after the separation 

 of the precii)itate, of a light sherry-wine color. 



The chemical effect of lime upon these saccharine juices is to decom- 

 pose the several salts of organic acids present, uniting with the acids 

 to form insoluble lime salts, which ai-e precipitated. It is said also to 

 render certain compounds, which were soluble in the acid solution, in- 

 soluble, and thus effect their removaL It also, especially in connection 

 with the heat, effects the destruction of the germs of fermentatiou, 

 and thus keeps the juice sweet. It is, on this account, advisable that 

 the mill, and those vessels in which the juice is stored, should be, when 

 not in use, rinsed out with water, to which enough lime has been 

 added to render it a little milky. 



DEFECATION WITH LIME. 



After the preliminary filtering or settling of the juice, it is taken 

 into the defecator, and there receives the treatment with lime. The 

 defecator may be either round or square; maybe heated by steam 

 coils or by direct heat; allhough steam is much to be preferred. It is 

 desirable that it should be deej), so that the sediment and scum formed 

 by defecation may, together, occupy but a small section of the depth, 

 thus permitting a large proportion of the clear defecated juice to be 

 drawn off directly, without the necessity of being passed through the 

 filters. A defecator 4 feet wide, 5 feet long, and S^ feet deep, is a 

 conveuieut size, and would hohl 500 gallons of juice. It should not 

 be filled more than about five-sixths of its capacity, in order to permit 

 the juice to be actively stirred about Avhile adding the lime, and to 

 avoid the danger of overflowing when it is brought to the boiling 

 point. So soon as the steam pipes are well covered Avith juice, or a 

 sufficient amount has run into the defecator to more than absorb all 

 the heat of the steam or fire, the heat may be applied; and when 

 enough juice has been brought into the defecator, the tempering with 

 lime may begin. For this purpose, a bucket of the cream of lime, w itli 

 a dipper for ladling it out, an assistant, with a strong paddle, for stirring 



