GENERAL ANALYSES OF SORGHU^I JTICES, ETC. 245 



sujar over the open fire, without the use of bone-black, or of any chemical ex- 

 cept liaie. I send you a sample of the sugar obtained. It was not washed in 

 the centrifugal, and so is darkened by the adherina alkaline syrup. Still, the 

 sample polarized 90 per cent pure sugar. I got exactly one-half the weight of 

 the boiled syrup in this sugar at the first running. The syrup I filtered through 

 bone-black to remove the lime. From it I got 50 per cent of sugar at second 

 running, a sample of which I also inclose. Thus I obtained without any method 

 of evaporation but open fire, 75 per cent of sugar from the boiled juice. 



I kept a part of my canes for five weeks in a shed, a part of the time at a 

 freezing temperature. December 4th. I worked some of these, and got. by the 

 diffusion process, 10 per cent of weight of canes in excellent sjTup, weighing 

 twelve pounds to the gallon, and of qualiy equal to that from the same cane 

 when first cut. 



I will now make a few suggestions for the profitable making of sugar from 

 sorghum. Two conditions are needed: 1. The cane should not be worked until 

 nearly ripe; the seed should be hard before the cane is cut. 2. The same pro- 

 cesses, so successfully applied to the beet in Europe, should be applied to the 

 sorghum. These processes are, briefly, as follows: 



1. The juice should be treated with a very considerable excess of lime, so as 

 to make it decidedly alkaline, at a temperature not exceeding 1G0° F. With- 

 out this excess of lime, a perfect defecation is impossible. 



2. The lime should then be almost wholly precipitated in the juice, by the 

 injection of carbonic acid gas. 



3. The slightly alkaline thin juice should then be filtered through cloth by 

 filter presses, or otherwise. 



4. It should then be passed through bone-black, and thoroughly decolorized. 



5. It should then be boiled down, either by open evaporator, or, far better 

 and cheaper, by exhaust steam in a double-effect vacuum pan to about 25° 

 Ban me. 



6. It should again be filtered through fresh bone-black, to remove all color. 



7. It should then be grained in the vacuum pan. 



8. It i-hould be purged in a centrifugal. 



The first product should be standard granulated sugar; the second product 

 should be bright yellow, and the third product light brown, refined sugar — a to- 

 tal product of about "5 per cent of the boiled juice. The process above de- 

 scribed will be substantially adopted when the manufacture of sugar from sor- 

 ghum is put upon its permanent business basis. It will be done, if at all, on a 

 large scale, and with large profit. 



The gumminess and difficulty of crystallization complained of in sorghum is 

 due either to unripeness, or to injury by frost, or to an imperfect defecation. No 

 properly defecated juice ever needs to be skimmed while boiling It must be 

 remembered that syrups designe-d for sugar require different treatment Irom 

 those which are not intended to crystallize. The presence of gum and vegeta- 

 ble matter add to the volume of -syrup, without greatl\" deteriorating its color, 

 if carefully handled, but is extremely detrimental to crystallization. No subse- 

 quent manipulation will cure an imperfect defecation. 



Another important consideration is, that the mills now in use, no matter how 

 powerful, do not express more than about two-thirds of the saccharine juice. These 



