682 LlLIACEiE. 



Malayan Peninsula. Its wood constituted a drug^ which was, down to 

 the beginning of the present century, generally valued for use as incense, 

 but now esteemed only in the East. 



Structure of the Leaf — The stout fleshy leaves of an aloe have 

 a strong cuticle and thick-walled epidermis. Their interior substance 

 is formed of very loose, large-celled, colourless pulp, traversed by 

 vascular bundles, which, on transverse section, are seen to be accom- 

 panied by a group of large thin-walled cells" containing the bitter juice 

 which constitutes the drufj under notice. These cells, on a longitudinal 

 section, are seen to be considerably elongated, adjoining a single row of 

 smaller, prismatic, truncated cells,^ by which the former are separated 

 from the cortical layer. The prismatic cells contain a yellow juice, 

 apparently different from that which yields aloes. The cortical tissue 

 is filled with granules of chlorophyll, and exhibits between the cells 

 groups of needles of calcium oxalate. Similar crystals are also found 

 sparingly in the pulp. 



The transparent pulp-tissue* is rich in mucilage, which after dilution 

 with water is precipitated by neutral acetate of lead, but is not coagu- 

 lated by boiling. 



The amount of bitter principles in the leaf probably varies with the 

 age of the latter and with the season of the year. Haaxman mentions 

 that, in Cura9ao, the maximum is found when the leaves are changing 

 from green to brown. 



Cultivation and Manufacture— In Ba.rhados,^ where Aloe vulgaris 

 is systematically cultivated for the production of the drug, the plants 

 are set 6 inches apart, in rows which are 1 to 1| foot asunder, the 

 ground having been carefully prepared and manured. They are kept 

 free from grass and weeds, but yams or pulse ai-e frequently grown 

 between them. The plants are always dwarf, never in the least degree 

 arborescent ; almost all of those above a j^ear old bear flowers, which 

 being bright yellow, have a beautiful effect. The leaves are 1-2 feet 

 long; they are cut annually, but this does not destroy the plant, which, 

 under good cultivation, lasts for several years. 



The cutting takes place in March and April, and is performed in the 

 heat of the day. The leaves are cut off" close to the plant, and placed 

 very quickly, the cut end downwards, in a V-shaped wooden trough, 

 about 4 feet long and 12 to 18 inches deep. This is set on a sharp 

 incline, so that the juice which trickles from the leaves very rapidly 

 flows down its sides, and finally escapes by a hole at its lower end into 

 a vessel placed beneath. No pressure of any sort is applied to the 

 leaves. It takes about a quarter of an hour to cut leaves enough to fill 

 a trough. Tlie troughs are so distributed as to be easily accessible to 

 the cutters. Their number is generally five ; and by the time the fifth 



1 Hanbury, Science Papers, 1876. 263 ; letss, and is actually used as food in times of 



also Fluckiger, Die Frankfurter Liste, scarcity in some parts of India. — Stewart, 



Halle, 1873. 37. (Archiv der Pharm. cci. Punjab Plants, 1869. 232. 

 511). — For full historical information see ^¥ov the particulars we here give re- 



Heyd, Levantehandel, ii. (1879), 559. specting Barbados aloes, we have cordially 



- The cells lettered e in Berg's figure C, to thank Sir R. Bowcher Clarke, Chief 



T^\a,iQi\.f. oihxs " OffizineUe Geivcichse" Justice of Barbados, and also Major- 



3 The cells (?, in Berg's figure. General Munro, stationed (1874) at Bar- 



* This central pulpy tissue is quite taste- bados in command of troops. 



