NORTHERN SUGAR INDUSTRY. 



57 



the acid solution should not be greater than is indicated by the proportions of sul- 

 phuric acid and water before stated. 



This acid solution is to be added to the defecated juice in the tank preferably in 

 the proportion of five hundred cubic centimeters of acid solution to one thousand 

 gallons of juice. I have found this proportion to work well with sorghum juice It 

 can be exceeded, probably, to a considerable extent without danger, though with no 

 perceptible advantage in results. Care, however, is to be taken not to add too much 

 of the acid solution , as the consequence might be to invert the sugar. The effect of 

 the acid solution upon the defecated juice is to throw clown the gum, or mucilage, 

 some of which is actually precipitated immediately, and all eventually, if the juice 

 is allowed to stand long enough for the light flocculentmaterial to gravitate to the 

 bottom. The success of the operation is at once manifested by the rising of sulphur- 

 ous fumes from the juice, the odor of which is plainly perceptible. 



As the deposition of the light mucilaginous material requires some delay, it is bet- 

 ter, in order to save time, to separate it out by means of a filter press of any suitable 

 construction, from which the filter juice emerges clear. It will be seen that this pro- 

 cess gives a cold defecation, and thus accomplishes a result of great value and im- 

 portance. A slightly better grade of sugar can be made, however, by conducting the 

 juice to the defecating vessels and there warming it nearly to the boiling point before 

 passing it through the filter press ; but this warming of the juice is not essential to 

 the production of excellent sugar by the aid of my process, as described. 



In the cold process, as I have described it, the juice parses fioni the filter presses 

 directly to the vacuum pan, thus entirely dispensing with defecators and clarifiers. 

 Care, however, must be taken that the filter press is properly worked, and that none 

 of the scum is allowed to mingle with the juice. In the warm process the juice passes? 

 as already stated, from the defecators to the filter press, and thence to the clarifiers. So 

 far as the relative advantages of the two processes are concerned, the cold process 

 requires greater care in operation, and produces almost if not equally as good a grade 

 of sugar, and does away with defecating and clarifying vej>sels and the skilled labor 

 and expenses attendant upon their use. The warm process, on the other hand, re- 

 quires less care in its general operation, but involves the use of defecators and clari- 

 fiers to compensate for such lack of care, and produces a grade of sugar which a very 

 experienced eye only would class as of better grade than that made by the cold 

 process. When treated by either process, the course of the juice after leaving the 

 vacuum pan is the same as already set forth. The resulting sugar is free from gum, 

 or very nearly so, and is generally of considerably better quality, both in grain, color? 

 and test than that made without the use of the weak acid solution. 



An important advantage of my invention is as follows : It is well known that cane- 

 juice, after being expressed, will ferment in a very short time, and inversion of the 

 sugar is the result, so that it is available only for the manufacture of alcohol or x^oor 

 molasses. After the juice is treated with the sulphureted lime mixture and the acid 

 solution, as 1 have before described, it will remain unchanged, and no fermentation 

 will take place as long as the sulphurous acid fumes continue to be emitted from it, 

 whether it is exposed to the air or not. I have kept such juice exposed to the air in 

 a warm room for three month thout detecting perceptible deterioration in it. 



The foregoing process I have ('escribed as I have practically applied it to the juice 

 of the sorghum plant, the crop being raised in the State of New Jersey. I have 

 found it to be applicable equally well to the ordinary sugar-cane and to the manu- 

 facture of molasses sugars from molasses imported from the West India Islands. It 

 is equally ajjplicable to the improvement of any raw sugars, these being dissolved in 

 water prior to the addition of the lime mixture and acid solution. 



It will be observed from the foregoing that in the processes described the liquor 

 remains acid — that is, gives an acid reaction to the test paper throughout — and in 

 this respect the said processes differ materially from ordinary lime or lime and sulphur 



