28 



It is seen from the above data that the mean total sugar in the free 

 liquor equals 9.44 per cent, and in the juice expressed from chips from 

 same equals 9.43 per cent. 



This method of extraction with sorghum chips is, therefore, open to 

 the objection of inverting a portion of the sucrose when the canes are 

 not fresh. It is seen that 4 per cent, of sucrose present has been changed 

 into reducing sugar. As the second of the analyses shows, this change 

 has taken place entirely without the cell, the composition of the juice 

 remaining in the cells being sensibly the same as that of the normal 

 juice of the cane. 



These results are of extreme interest. They show most conclusively 

 that in the process of diffusion at a high temperature there is a notable 

 inversion of the sucrose when the canes are not in proper condition. 

 Further than this, it is shown that this inversion takes place in the 

 sugar in the free liquor and not in the sugar remaining in the fiber of 

 the cane. In nearly every case the free liquor was poorer in sucrose and 

 richer in glucose than that in the pulp. 



To correct the acidity in the battery, and thus avoid inversion, the 

 following methods were tried : 



(1) The limed juice used in the carbonatation-tauks was added to the 

 cell of fresh chips little by little until enough was used to neutralize 

 the acid. Two serious objections were found to this procedure : (a] The 

 proper control of the quantity to be added was impossible, The juice 

 would at times become strongly alkaline and highly colored; (b) the 

 lime seemed to prevent the extraction of the sugar. The total solids 

 of the diffusion j uice under this treatment ran down rapidly from 11 per 

 cent, to 4 per cent. This was due either to the coagulated albuminous 

 matters preventing the osmotic action or to the formation of an insolu- 

 ble lime sucrate, which remained in the chips. The method, therefore, 

 had to be abandoned. 



(2) Lime-water was added to the tank supplying the diffusion battery 

 in such proportions as to furnish alkali enough to nearly neutralize the 

 free acidity of each cell of chips. This water entered the cell next to 

 be emptied of exhausted chips. All the lime in suspension was at once 

 filtered out, and that in solution was not sufficient to neutralize the 

 acidity in the cells in advance. 



(3) Addition of lime bi- sulphite. To test the efficiency of lime bi- 

 sulphite in preventing inversion during extraction it was added to the 

 water in the feed-tank for the battery in quantities equal to one-half 

 gallon for each diffusion. It was also used in the extraction flask with 

 the results to follow. 



(4) The addition of freshly precipitated carbonate of lime to the ex- 

 traction bottle. This method was suggested by Prof. M. Swensou. 

 The analyses show that the acidity was diminished by two-thirds, and 

 the inversion of the sucrose largely prevented by the treatment. If a 

 few pounds of such a carbonate could be evenly distributed in the 



