197 

 198.-SWEBT CASSAVA. 



In an analysis published by E. Francis, Esq., late Government 



Analyst in Trinidad in 1877, the mean yield of Hydrocyanic Acid 



in Cassava was given as follows : — 



Siveet Cassava. Bitter Cassava. 



Mean % HCN -0168 ... Mean % HCN "0275 



Highest % HCN -0238 ... Highest % HCN -0442 



Lowest % HCN -0113 ... Lowest % HCN -0132 



Thinking it possible that the variety of Sweet Cassava commonly 

 grown in Trinidad was probably not the best variety, I imported the 

 Jamaica kind, which proves in appearance very distinct from that 

 of Trinidad and gives on examination by the Government Analyst the 

 following yield of Hydrocyanic Acid, viz. : 0-01017 % — which is 

 lower than the lowest return obtained by Francis out of fifteen sam- 

 ples. As pointed out to me in conversation by the Government 

 Analyst the returns given by a single analysis are not sufficient 

 to show that there is a definite diiferencc in the yield of HCN 

 between the two varieties but it certainly shows that there is grounds 

 for further examination. 



I have with myself and family and friends partaken of these 

 roots freely Avhen boiled without the slightest harm, and their appear- 

 ance is certainly quite distinct from the Trinidad variety of Cassava. 

 Dr. Morton's question, whether Sweet Cassava ever becomes bitter is 

 however not yet satisfactorily answered, but I may mention in con- 

 nection therewith that my friend Dr. G. C. Henderson of Jamaica 

 who was lately travelling in Columbia, states that Jamaicans who 

 have imported the Bitter Cassava in preference to the Sweet as a 

 starch producer, find in Columbia that the bitter variety becomes sweet. 



One thing is certain that the less poison the less danger, and it 

 behoves us to procure for table use that variety which is harmless — 

 rather than risk the use of the more dangerous varieties. Bitter 

 Cassava however of the most poisonous kind Avhich has been sliced 

 thin and then dried in the sun or artificially is capable of being used 

 for food without the slightest danger, as the elements of danger are 

 dispersed in the drying process. 



ANALYSIS. 



The Supt. of the Royal Botanic Gardens. 



The sample of "Sweet Cassava" contains 0-01017 % of Hydrocyanic acid. 



WALTER H. INCE, 



Adg. Government Analyst. 



