MIAMI, FLA., 1905. 



27 



SEASON OF 1905. 



In the spring of 1905 a crop of cassava was grown on new ground 

 in Miami from the same pedigreed varieties raised in the previous 

 year, and a chemical study was made of the crop in January of 1906. 



As the purpose in view was to establish a vigorous strain by obtain- 

 ing a two years' growth of the same root, only one series of observa- 

 tions was made, the results of which are given in Table IX. The 

 figures for h3 T drocyanic acid are below the semibitter standard, though 

 in the majority of cases they are higher than those obtained for the 

 same variety in the previous year, and when tabulated with the results 

 for the same year at Biloxi, the opposite condition is found i. e., the 

 Miami tubers are higher in hydrocyanic acid than those grown at 

 Biloxi. ^ It would appear, therefore, that the hydrocyanic acid content 

 of these plants is beyond question a variable factor, even in the same 

 varieties grown under the same climatic conditions. 



In connection with these figures there are given in Table IX some 

 results obtained on the same pedigreed numbers grown in Cuba. 

 These analyses were made by the analyst at the Cuban central agricul- 

 tural station and are published with his permission. The method of 

 anal} r sis of the Trinidad station was used, namely, that of inciting 

 cyanogenetic action and determining the amount of h} 7 drocyanic acid 

 produced. This method of procedure is based on the hypothesis that 

 a similar effect is produced during digestion, and therefore one should 

 determine the amount of h} T drocyanic acid which will be formed and 

 liberated after the tuber is taken into the stomach, and not the amount 

 present in a free state. An obvious fallacy in this argument is 

 brought out in the evidence relating to cases of cassava poisoning, 

 there being authentic cases in which death ensued in fifteen minutes 

 after eating. The hypothesis, therefore, is untenable unless the acid 

 is formed much more rapidly in the stomach than in artificial diges- 

 tion, in which from several days to two weeks are necessary to com- 

 plete the process, though in fact it continues until decomposition 

 begins. 



TABLE IX. Comparison of percentages of hydrocyanic acid found in the same varieties 

 of cassava grown at Miami, Fla., Biloxi, Miss., and in Cuba, 1905. 



