SUG 



rrystallizable sugar obtainnd from 

 canes, wliich, as \vc have seen, all 

 contain veiy nearly the same ((iiaii- 

 tily of this substance, prove that llie 

 processes of concentration and puri- 

 fication of the sap also contribute to 

 the loss which has been indicated. 

 M. PflifTot has pointed out several 

 causes wliich concur to deteriorate 

 sugar : among ilic number : 1. A vis- 

 cous fermentation, which renders the 

 sap thick and stringy, like mucilage, 

 by which the boiling becomes difficult 

 and the crystallization of the sugar 

 which has escaped change is render- 

 ed imjierfect. 2. An acidity, which 

 takes place when the juice is not run 

 at once into the coppers and boiled, 

 an acidity which requires the addi- 

 tion of lime to destroy or to prevent 

 it. The alkaline earth, as I have had 

 occasion to say, is by no means indis- 

 pensable ; its utility, under ordinary 

 circumstances, is probably confined 

 to assistmg the defecation by form- 

 ing an insoluble precipitate with some 

 of the organic substances which are 

 always met with in small quantities 

 in cane juice ; perhaps, also, to ma- 

 king an earthy soap with the fatty 

 matters which adhere to the cane 

 and are expressed in the crushing. 

 When lime is added to correct acid- 

 ity, it forms an acetate or a lactate, 

 salts which are peculiarly soluble, 

 uncrystallizable, and which necessa- 

 rily retain a quantity of sugar in the 

 sirupy state. 3. The presence of 

 certain mineral salts in the cane. 

 Conmion salt, for instance, in coin- 

 bin ing with sugar forms a deliques- 

 cent compound, in which one part of 

 salt is united with six parts of sugar ; 

 such a compound as this of course 

 renders a large quantity of sirup in- 

 di.sposed to crystallize. It is therefore 

 impossible to be too cautious, accord- 

 ing to M. Peligot, in the choice of 

 manure for a cane field ; that which 

 contains any common salt must 

 needs be injurious in one way, how- 

 ever advantageous it may be in an- 

 other. The entire absence of this 

 salt in the soil of plantations which 

 are very remote from the seashore 

 is perhaps one of the causes which 

 768 



SUL 



increases the quantity of sugar ob- 

 tained from the crop, and makes it 

 inore easily manufactured in suirh 

 districts. 



" M. Codazzi reckons the quantity 

 of white sugar produced by a hectare 

 of land (2 473 acres), planted with 

 the Otaheite cane in the province of 

 (^araccas, at 1875 kilogrammes, or 

 3fi cwt. 3 qrs. 9 lbs. avoir., which 

 is at the rate of 15 cwt. 1 qr. 10 lbs. 

 per acre. Taking 7| per cent, as the 

 average quantity of sugar obtained, 

 the weight of cane brought to the 

 mill must obviously have amounted 

 to 19,134 kilog., or 18 tons, 15 cwt. 3 

 qrs. 10 lbs. ; or 7 tons, 1 1 cwt. 3 qrs. 

 25 lbs. per acre. Assuming the av- 

 erage composition of the plant to be, 



Wood (dry) HO 



Sugar (minimum) 15 5 



Water 73-5 



1000 



one acre of land will consequently 

 yield a crop of 



Tons. Cwts. Qr.i. Lbs. 



Wood (dry) . . 16 2 24 



Sugar .... 1 3 2 6 



Water • • • • ^ H 2 12 



7 11 3 25 



" The trash of the sugar cane un- 

 dergoes rapid fermentation ; it soon 

 exhales a distinct smell of vinegar, 

 and almost the whole of the sugar 

 which is left in it is destroyed." 



SUGAR OF LEAD. Acetate of 

 lead, so called from its sweet taste. 

 It is much used in lotions; and in 

 solution with a little vinegar forms 

 Goulard's lotion. It must not be 

 used incautiously, as it is poison- 

 ous. 



SULCATE. Marked with furrows, 

 or parallel deep lines. 



SULPHATES. Salts of sulphuric 

 acid. The principal in agriculture 

 are the sulphate of lime (see Gyp- 

 sum), the sulphate of soda (Glauber's 

 salt), and sulphate of potash. The 

 latter is, however, too expensive ; it 

 is found in the ashes of some plants. 

 Glauber's salt may be obtained for 

 $1 to $1 50 the 100 pounds, and is 

 serviceable as a steep, or as a manure 

 in gardens for the cruciferous plants. 

 The chief value of the sulphates as 

 manures arises from the necessity for 



