5 



D. — SUGAR CANE MANURES. 



Summarg of conclusions arrived at on the action of Manures for Suaar Canes at the Experiment Fields, 

 Barbados, by J. B. Harrison, Esq., JU.A,, Island Professor of Chemistry and Agricultural Sciences, 

 and J. R. Bovell, Esq., taken from their Second Annual Report, 1887, 



1. Manuring the sugar cane with only the mineral constituents of manures is useless, the cane 

 not having the power, as stated by M. Ville, of assimilating free nitrogen from the air. 



2. The addition of readily available nitrogen to the purely mineral manures produce large in- 

 creases in the weight of canes grown, but excessive dressings, (over 3 cwt. of sulphate of ammonia to 

 the acre) cause a marked decrease in the richness and purity of the juice. 



3. Under the climatic conditions existing at Dodds during the years 1885, 1886 and part of 1887, 

 and upon the soil of the experimental fields, nitrate of soda was decidedly inferior to sulphate of am- 

 monia, as a source of nitrogen. 



4. The addition of superphosphate in moderate proportions to manurings of nitrogen and potash 

 causes a very great increase in the yield of canes, and in the available sugar in the juice per acre. 



5. The addition of superphosphate in quantities beyond that capable of supplying about 751bs of 

 " soluble phosphates" per acre, (equivalent to about 16 per cent, of "soluble phosphates in the ordi- 

 nary manuring of one ton to five acres of commercial sugar cane manures) does not produce a 

 corresponding increase, and if applied in very large proportions may even reduce the produce below 

 that obtained from manuring with nitrogen and potash only. 



6. The addition of potash to manurings of superphosphate and nitrogen, may not increase the 

 yield of total produce to any very marked extent, but from its tendency to increase the development of 

 the canes causes a large increase in the amount of " available sugar" in the juice per acre. 



7. The presence of potash in the manures in rather high relative proportions apparently tends to 

 increase the amount of sucrose in the canes. This point is worthy of further investigation. 



8. The presence of an excess of Potash in the manures, does not injurionsly affect the purity of 

 the juice by increasing the glucose, or appreciably the amount of potash salts contained in it. 



[A few copies of the full Report have been kindly sent to the Botanical Department, and have been 

 distributed amongst Sugar Planters in Jamaica.] 



E. — WEIGHT OF BARK FROM CINCHONA TREES (Cinchona officinalis.) 



Enquiries having been made as to the amount of bark that may be expected from trees of various 

 heights, 10 trees were cut down and barked with the following result: — 



I 



II. 



III. 



IV. 



V. 



VI. 



VII. 



VIII. 



IX. 



X 



XI. 



XII. 



Number of Tree. 



1 Height in feet and 

 inches. 



Branched at — feet 

 from ground. 



| Circumference at 

 base in inches. 



Circumference at 

 first branch in 

 inches. 



Circumference of 

 first branch in 

 inches. 



Weight of wet 

 bark from stem 

 in ounces. 



Weight of dry- 

 bark (taken ut 

 one-third. ) 



Weight of wet 

 bark from stem 

 | and branches in 

 ounces. 



Weight of dry 

 baik (taken at 

 one-third.) 



Weight of wet 

 bark from root 

 in ounces. 



Weight of dry 

 bark (taken at 

 one- third.) 



1 



2 

 3 



Average 



4 

 5 

 6 

 7 



Average 



8 

 9 

 10 



Average 



6.4 

 7.8 

 10.0 

 8.0 

 9.10 

 10.0 

 15.3 

 20.6 

 13.11 

 10.0 

 11.0 

 14.3 

 11.9 



4 



4 



10 

 11 

 15 

 16i 

 13 

 6 



12 



9£ 



9 



4 



n 



104 



2 

 5 

 4 



15 

 10 

 28 

 17| 



5 



n 



6 



33 



60 

 120 

 156 



921 



18 



46 



48 



37i 



11 



20 

 40 

 52 

 31 

 6 

 15* 

 16 

 12* 



10 

 24 

 14 

 16 



k 

 8 



U 



The trees, Nos. (1) to (7) are from the Plantation at Newhaven Gap, which was first made in 

 1868. It is impossible now to ascertain the age of any of these trees, as some are seedlings and some 

 are shoots from coppiced trees. There are probably very few of the original trees left, perhaps No. (7) 

 is one of these. No. (1) may be taken as an example of a tree six years old. 



Nos. (8) to (10) are from the Plantation called " Upper Buzza" made in 1879-80. These trees 

 are therefore 7 or 8 years old. 



The dry bark in the Table has been taken at one-third the weight of the wet bark. This would 

 give 1 libs. 2ozs. for dry stem bark; the actual weight being 121bs. Root bark does not lose so much 

 in drying, for instead of one-third (viz. lib.), more than one-half was obtained — lib 12ozs. One-third, 



