INTRODUCTION. 



41 



Fig. 40. 



Fig. 41. 



Tahiti Arrow-Root. 



Fig. 42. 



Portland Ar- 

 row-Root. 



Arrow-Root, East Indian. A fine white powder. 

 It looks like a finely powdered salt, it has not 

 the firmness of the West Indian, nor like that, does it 

 crackle on being rubbed between the fingers. Under 

 the microscope it appears to consist of ovate or oblong- 

 ovate, flattened granules, usually with a short neck 

 or nipple-like projection. The hilum is at the small 

 extremity ; it is very small, circular and indistinct. 

 The rings are numerous, closely set together and Whit e East Indian Arrow Root 

 delicate. The product of Curcuma angustifolia, $-c. 



Arrow-Root, Tahiti. A fine white powder, often 

 with a slight musty smell. Under the microscope it 

 appears to consist of circular, mullar-shaped or poly- 

 hedral particles. The mullar-shaped particles are 

 often narrowed at base, and seem to be hollowed out. 

 The hilum is small and circular, and cracks in a 

 linear or stellate manner. The rings are few and 

 somewhat indistinct. Produced by Tacca pinnati- 

 fida. 



Arrow-Root, Portland. A white powder. Under the micro- 

 scope the particles appear very minute. They are circular, 

 mullar-shaped or polygonal. The hilum is circular, and seems 

 to be at the bottom of a slight depression ; it cracks in a linear 

 or stellate manner. It is obtained from Arum maculatum, and 

 is probably identical with the starch afforded by A. triphyllum. 



Tous les mois, is an arrow-root 

 with a satiny appearance, and looks 

 more like potato starch than the above 

 mentioned feculas. Under the mi- 

 croscope it is found to consist of larger 

 particles than any other known starch. 

 They are oval or oblong, usually more 

 or less ovate. The hilum is circular, 

 and usually at the smaller extremity ; 

 occasionally it is double. The rings 

 are numerous, regular, and close set. 

 They and the hilum are often cracked. 

 It is procured from a species ofCanna. 



Potato Starch. A white powder. 

 Under the microscope it appears to 

 consist of particles of various shapes and sizes, the regular form probably 

 being ovate; they have concentric rings on their surface. The hilum is cir- 

 cular, and is often double. The cracks observable in some of the particles 

 usually commence at the hilum. The size of the particles is greater than 

 those of the other feculas, with the exception of the last mentioned. 



Potato Sago. An article is manufactured from potato starch in imitation 

 of pearl sago, and is often sold for it. Under the microscope it is found that 

 the particles of the artificial are larger than those of the true sago, and that 

 they are more regularly oval and ovate, more distinctly annulated, smoother 

 and less broken. When cracks occur at the hilum, they are usually in .two 

 diverging fissures. 



Sago. There are two forms of sago ; one pulverulent or sago flour, the 



Fig. 43. 



Tous les mois. 



