[ 71 3 



latumj) Salep (Orchis mascula^) Flower de luce, or 

 Water Flag (Iris Pseudacorus^ Stinking Gladwyn (Iris 

 fcKtidissima^) Earthnut (Bimiiim Bulbocastanum.} 



3. Sugar in its purest state is prepared from the 

 expressed juice of the Sac char urn Offktnarum, or sugar 

 cane ; the acid in this juice is neutralized by lime, 

 and the sugar is crystallized by the evaporation of the 

 aqueous parts of the juice, and slow-cooling : it is 

 rendered white by the gradual filtration of water 

 through it. In the common process of manufacture, 

 the whitening or refining of sugar is only affected in a 

 great length of time ; the water being gradually suf- 

 fered to percolate through a stratum of clay above the 

 sugar. As the colouring matter of sugar is soluble 

 in a saturated solution of sugar, or syrup, it appears 

 that refining may be much more rapidly and cecono- 

 mically performed by the action of syrup on coloured 

 sugar.* The sensible properties of sugar are well 

 known. Its specific gravity according to Fahrenheit 

 is about 1.6. It is soluble in its own weight of water 

 at 50 ; it is likewise soluble in alcohol, but in smal- 

 ler proportions. 



* A French gentleman lately in this country (England), stated to the West 

 India planters, that he was in possession of a very expeditious and economical 

 method of purifying and refining sugar, -which he was willing to communicate to 

 them for a very great pecuniary compensation. His terms were too high to be 

 acceded to. Conversing on the subject with Sir Joseph Banks, I mentioned to 

 him, that I thought it probable that raw sugar might be easily purified by passing 

 syrup through it, which would dissolve the colouring matter. The same idea 

 seems to have occurred about the same time, or before, to Edward Howard, Esq, 

 who has since proved its efficacy experimentally, and has published an account of 

 his process. 



