ALOES 435 



greyish green or sometimes pale yellowish powder, and when this is 

 mixed with a little sulphuric acid and the vapour of nitric acid blown 

 over,it, a deep blue coloration is produced. 



These last three characters are so distinctive that Natal aloes is one 

 of the easiest to identify. 



WEST INDIAN ALOES 



5. Barbados Aloes. But very little aloes is now produced in the 

 island of Barbados, and that which bears this name is in reality 

 prepared in the Dutch islands of Curasao, Aruba, and Bonaire ; 

 it is therefore, often and more appropriately, termed Cura9ao aloes. 

 The plant which yields it appears to be Aloe vera, Linne, or possibly 

 A. chinensis, Baker. 



Curayao or Barbados aloes arrives usually in boxes, sometimes in 

 gourds. It occurs in the vitreous as well as in the livery variety ; 

 the former, commercially known as ' Capey ' Barbados, may become 

 opaque on keeping, a change to be ascribed to the slow crystallisation 

 of the aloin. It is also by no means uncommon to find packages that 

 are partly filled with glassy, partly with opaque, aloes ; such differences 

 in the appearance are probably due to slight differences in evaporating 

 the juice. 



Livery Cura9ao aloes of good quality varies in colour from yellowish 

 or reddish brown to chocolate brown, lower grades being black and 

 occasionally burnt. It breaks with a dull, waxy, even fracture, 

 small splinters exhibiting under the microscope numerous minute 

 crystals of aloin. It closely resembles Zanzibar aloes, and, in fact, 

 can be distinguished (apart from chemical tests) only by its distinctive 

 odour. 



Vitreous Cura9ao aloes, which is not a highly esteemed variety, is 

 distinguished from the livery by its transparency. It has usually, 

 in small fragments, a garnet-red colour ; in other respects it resembles 

 the foregoing. 



The student should have little difficulty in identifying the foregoing 

 varieties of aloes. Two only (Cape and Cura9ao) are commonly met 

 with in the vitreous form, and they are easily distinguished both by 

 their colour and by their very different odour. - Five (Socotrine, 

 Zanzibar, Natal, Cura9ao, and Uganda) are hepatic. Of these the 

 odour of the Natal distinctly recalls that of Cape, whilst the greyish 

 green or pale yellowish brown powder is characteristic. Uganda aloes 

 is readily identified by its bronze-gold colour. Both Natal and 

 Uganda aloes are practically obsolete. Socotrine aloes is remarkable 

 for its unpleasant odour and uneven, porous, fracture. Zanzibar and 

 hepatic Cura9ao are very similar in appearance, but differ in odour ; 

 these are the only two likely to be confused, and if necessary a chemical 

 test must be applied. 



