634 CANNACEJ5. 



mined ; it is said to agree with Oawna edidls Ker (C indica Ruiz et 

 Pavon).^ 



The starch, which bears the same name as the plant, is a dull white 

 powder, having a peculiar satiny or lustrous aspect, by reason of the 

 extraordinary magnitude of the starch granules of which it is composed. 

 These granules examined under the microscope are seen to be flattened 

 and of irregular form, as circular, oval, oblong, or oval-truncate. The 

 centre of the numerous concentric rinojs with which each ijranule is 

 marked, is usually at one end rather than in the centre of a granule. 

 The hilum is inconspicuous. The granules though far larger than those 

 of the potato, are of the same density as the smaller forms of that 

 starch, and, like them, float perfectly on chloroform. When heated, 

 they begin to burst at 72° C Dilute hydrochloric acid acts upon them 

 as it does on arrowroot. 



Canna starch boiled with 20 times its weight of water aftbrds a 

 jelly less clear and more tenacious than that of arrowroot, yet applicable 

 to exactly the same purposes. The starch is but little known and not 

 much esteemed in Europe ; it was exported in 1870 from St. Kitts to 

 the amount of 51,873 lb, besides 5,300 lb arrowroot starch.^ 



Curcuma Starch, Tikor, Tihhar. — The pendulous, colourless tubers 

 of some species of Curcuriia, but especially of G. angustifolia Roxb. 

 and C. leucorrhiza Roxb., have long been utilized in Southern India 

 for the preparation of a sort of arrowroot, known by the Hindustani 

 name of Tikor, or Tihhur, and sometimes called by Europeans Ea^t 

 Indian Arrowroot? The granules of this substance much resemble 

 those of Mavanta, but they are neither spherical nor egg-shaped. On 

 the contrar}'^, they are rather to be described as flat discs, 5 to 7 mkm. 

 thick, of elliptic or ovoid outline, sometimes truncate ; many attain a 

 length of 60 to 70 mkm. They are always beautifully stratified both 

 on the face and on the edge. The hilum is generally situated at the 

 narrower end. We have observed that when heated in water, the 

 tumefaction of the grains commences at 72^ C 



Curcuma starch, which in its general properties agrees with common 

 arrowroot, is rather extensively manufactured in Travancore, Cochin 

 and Canara on the south-western coast of India, but in a very rude 

 manner. Drury* states that it is a favourite article of diet among the 

 natives, and that it is exported from Travancore and Madras ; we can 

 add that it is not known as a special kind in the English market, and 

 that the article we have seen ottered in the London drug sales as East 

 Indian Arroicroot was the starch oi Mavanta. 



'Fig. in Bentley and Trimen's Medic. ing this arrowroot at Cochin, have been 



Plants, parts (1876). kindly forwarded to us l)y A. F. Sealy, 



" Page 102 of the Reports quoted at p. Esq. of that place. 



033, note 2. •• Useful Plants of India, ed. 2. 1873. 168. 



^ Living roots of the plant used for niak- 



