METHOD OF DEFECATION WITHOUT ANIMAL CHARCOAL. 103 



of sufficient size to supply the requisite steam for heating 

 the defecating vessels. The arrangement could, under 

 other circumstances, be modified according to convenience 

 or necessity. 



The first and most important object, is to raise the 

 temperature of the juice, after its expression, to the boiling 

 point as rapidly as possible, and so prevent the tendency 

 to injury from atmospheric influence, and destroy or 

 arrest the action of the glutinous ferment, or "niatiere 

 globulaire," which becomes developed immediately after 

 expression, and is only destroyed by exposure to an 

 elevated temperature. It would be well, if it could be done 

 conveniently, to have the mill bed, upon which the juice 

 first falls, constructed with a double bottom of strong- 

 boiler plates, within which high pressure steam could be 

 admitted at pleasure, by a cock from the boiler ; this would 

 not only assist in heating the juice at once, but would pre- 

 vent the accumulation of any acid or ferment in the mill 

 itself, a circumstance which occurs to a certain degree even 

 in those mills w r hich are most carefully cleansed, and to a 

 most injurious extent in others which are not. I believe 

 that this plan has been tried in one of the French colonies. 

 It is open to the objection, that the framework of the mill 

 might be distorted, by the expansion of the lower portion, 

 from exposure to a high temperature ; but this might be 

 remedied by having a false double bottom unconnected 

 with the frame of the mill ; and perhaps it would be advan- 

 tageous if this was made of copper. Double metallic 



