694 PHILOSOPHICAL TRANSACTIONS. [aNNO 1790. 



But it is the custom in most of the West India islands to permit the canes to 

 rattoon ; that is, after the canes have once been cut down, for the purpose of 

 making sugar, they are suffered to grow up again, without replanting ; and this 

 generally for 3 or 4 years, but sometimes for 10, 15, or 20. In this mode of 

 culture the stools become larger every year, so as to grow out of the ground to 

 a considerable height, and by that means afford more 'and more shelter to the 

 ants' nests; therefore, for 2 or 3 successive crops, the canes should be replanted 

 yearly, so as not only to afford as little cover as possible for the ants' nests, but 

 continually to disturb such ants as may have escaped, in the business of propa- 

 gating their species. 



That considerable expense and labour will attend putting this method into ex- 

 ecution, cannot be doubted. An expensive cure however is better than none; 

 but from the general principles of agriculture, Mr. C. is of opinion, that the 

 planter will be amply repaid for his trouble, by the goodness of his crops, in 

 consequence of the superior tilth the land will receive in the proposed method. 

 Of this we have a proof in the island of St. Kitt's, where they constantly re- 

 plant their canes yearly; and it is very well known, that an acre of cane land 

 there gives a greater return than the same quantity in any other island. In St. 

 Kitt's, 5 hogsheads per acre is common yielding in good land. In Grenada, 

 from 2 to 3 hogsheads from plant canes, and half that quantity from rattoons. 

 Thus, though the St. Kitt's planter cuts only one half his cane land yearly, in a 

 given immber of years he makes a greater revenue than the Grenada planter on 

 the present mode of rattooning, when a of the cane land is yearly cut. 



Some may be of opinion, that it would be more advantageous to change the 

 produce than to pursue the proposed method ; on which Mr. C. observes, that it 

 appears -^ of the usual crop of sugar, thus produced, will be more advantageous 

 to the planter, when at the same time progress is making in destroying the sugar 

 ants, than a full crop of any other produce. In some very few situations cotton 

 perhaps may be excepted. As to coffee, it is to be considered that it gives no 

 return till the 3d year after planting, and not a full crop till the 5th. Cocoa 

 begins to bear in 5 years; but yields little till the 7th; and indigo not only ex- 

 ceedingly impoverishes the land, but is unhealthy to the negroes. Add to this, 

 that far the greatest part of sugar lands are unfit for the culture of any of these. 



JCX. Experiments and Observations on the Dissolution of Metals in Acids, and 

 their Precipitations ; with an Account of a New Compound Acid Menstruum, 

 useful in some Technical Operations of Parting Metals. By James Keir, Esq., 

 F. R. S. p. 359. 

 In the following paper, says Mr. K., I intend to relate 2 sets of experiments; 



one, showing the effects of compounding the vitriolic and nitrous acids in dis- 



