11 



Fig. 2, Plate i, shows Indian-corn starch in similar conditions. The 

 average size of the particles is the same in both instances, viz, 0.012 man- 

 The cassa\va particles are more irregular- in size, au-d a*re, moreover, to 

 be distinguished from the maize particles by greater evenness of out- 

 line. The cassava, however, more nearly resembles the maize starch 

 than it does any other well-known variety, and by reason of t'his resem- 

 blance could easily take the place of maize starch, in the kitchen and 

 laundry. 



Fig. 1, Plate n, shows cassava starch magnified 150 diameters and 

 viewed by pokirized light. Only the larger particles are well in focus, 

 nevertheless the cross can be seen on the smaller by close inspection. 



Fig. 2, Plate n, shows maize starch in similar condition. While it 

 would be difficult in all cases to distinguish these two starch'es by the 

 microscope, yet there are some points of difference, as have already 

 been noted, by means of which the expert may usually be successful in 

 the discrimination. 



The cassava which grows in tropical regions contains a notable per- 

 centage of hydrocyanic acid, so great, in fact, that it can not be used 

 directly as a food. The so-call'ed poisonous cassava is boiled, to expel 

 the. hydrocyanic acid before being used for feeding purposes. A care- 

 ful determination was made of the hydrocyanic acid in the fresh root 

 and the amount was found to be in considerable quantity, but not suf- 

 ficiently large to be alarming. Nevertheless, any possible danger could 

 be avoided before using the material as a food by subjecting it to a 

 sufficient heat to expel the hydrocyanic acid. The hydrocyanic acid 

 seems to be distributed throughout the pulp,. and particularly in the 

 juices which can be expressed from the pulp. ls.o inj-urious effect from 

 the hydrocyanic acid has ever been observed in the case of animals fed 

 on cassava in Florida. 



The bark of the root was also subjected to analysis, as will be seen 

 by reference to the following table. It contained no starch, the unde- 

 termined matter being chiefly digestible fiber and pentosans. 



The mineral matters extracted from the soil are distributed as indi- 

 cated in the table. The amount of ash in the root itself is quite low, 

 showing that the cassava plant does not require a soil very rich in 

 mineral constituents. The amount of mineral matter taken from the 

 soil by 100 kilos of the fresh root is approximately only half a kilo. 

 The albuminous matters are also present in small quantities, being 

 only slightly larger in weight than the ash itself. The plant, therefore, 

 is one which seems particularly suited to feed almost exclusively from 

 the air and water, and hence is one which could be recommended on 

 the sandy soils of Florida as a crop which would require the minimum 

 of fertilization. 



