1630.] The Sugar Cane. &J 



The canes, being ripe, are cut, and tied into bundles for the conve- 

 nience of taking to the mill. 



Chapter fifth contains many valuable observations on the vegetable 

 economy of the sugar cane, and concerning the juice of plants in general. 

 "In the last modification of the juice (of the sugar cane) the saccharine 

 mucous juice is entirely deprived of its yellow colour and balsamic smell, 

 while its saccharine taste is much more developed. This last state is that 

 which constitutes the essential salt of the cane. It is enclosed in cells, 

 and appears beautifully clear. As each cell is absolutely isolated, and as 

 there is no communication between them, this juice only escapes when 

 it is pressed out by the mills ; it can never flow out of the cane either 

 in the shape of syrup or concretion." 



When the canes or ratooris are ripe they are cut and carried to the 

 mills in bundles, and are there submitted to its action. They are com- 

 pressed twice between the rollers, by which means they are squeezed 

 perfectly dry. In this process the juice carries with it some of the 

 bruised cane, and the whole forms an homogeneous product which the 

 author denominates the expressed juice to distinguish it from that what is 

 subsequently clarified and concentrated. 



By simple exposure to the air and sun the watery parts evaporate and 

 leave sugar in the crystalline form ; but unfortunately the quickness with 

 which the juice passes into fermentation, makes this operation totally 

 impracticable on a large scale, and hence promptitude in boiling the juice 

 is absolutely necessary ; and it is also necessary to use an alkali to assist 

 in separating the feculent part. The expressed juice of the cane deprived 

 of its feculency, contains the sap and mucous juices, united with muci- 

 lage, forming together the cane liquor, a clear, transparent fluid of a 

 yellow colour. 



The saccharometer is recommended for ascertaining the specific 

 gravities of fluids, thereby to conduct the process of sugar boiling with 

 greater certainty and precision. A table is given of the quantity of 

 sugar contained in 100 Ibs, of good juice; and also of the quantity of 

 water that must be evaporated to reduce the same to the state of satu- 

 rated syrup taken at each degree of the saccharometer. 



This part of the work contains much valuable chemical information 

 regarding the boiling process and comparative value of the juice at 

 different periods, and under various circumstances, well worthy the 

 notice of sugar planters, especially at the present moment, when it is so 

 necessary to adopt every possible method for increasing the quality of 

 the produce of their estates, and for saving manual labour. 



" The result of an examination into the actual produce of a considerable 

 estate in Jamaica, during eleven years, gives 122 Ibs. of sugar as the 

 highest produce of 100 gallons cane juice; 96 Ibs. as the lowest, and 108 

 Ibs. as the average produce (p. J3 3 74. ;) but this varies very much in 

 different soils, islands, and seasons. Alkalis are injurious in proportion 

 to their activity in separating the mucilage from the feculent parts ; and 

 in the necessity of employing them to clarify the expressed juice we should 

 carefully seek for every means of judiciously conducting the operation. 

 This delicate and important office w, however^ generally performed in the 

 most slovenly and careless manner." 



In the manufacture of the juice into sugar, cleanliness is strictly 

 enjoined, the buildings and utensils minutely described, and valuable 

 practicable improvements indicated. " When the work of the boiling". 



M. M. New Series. Vol. X. No. 55. M 



