14 



CASSAVA. 



hydrocyanic acid collected and estimated in the usual way. A cor- 

 responding portion of the juice was treated with sulphuric acid, which 

 would have liberated the hydrocyanic acid from any base with which 

 it could have been combined. This mixture was also distilled and the 

 acid titrated, the similar results obtained on the treated and untreated 

 juice, as shown in the following table, indicating that no hydrocyanic 

 acid was present in a nonvolatile form: 



TABLE II. Determinations of hydrocyanic acid on samples prepared with and without 



sulphuric acid. 



The effect of fermentation on the content of hydrocyanic acid was 

 also tested by grinding 2 kilos of cassava and keeping it in a moist 

 condition. The fresh sample showed a content of 0.003 per cent of 

 hydrocyanic acid, when four days old 0.002 per cent was found, and 

 the sample was decomposed on the sixth day. 



A cassava meal made from a sweet variety was tested, 540 grams 

 being treated with water and distilled, and only a trace of hydrocyanic 

 acid was found. 



PEDIGREED VARIETIES OF CASSAVA GROWN AT BILOXI, MISS. 

 SEASON OF 1904. 



At this station thirty-nine pedigreed varieties were grown in the year 

 1904 by the Bureau of Plant Industry of this Department. Twelve of 

 these were direct importations from Porto Rico and the remainder 

 were taken from the subtropical station at Miami, Fla., where they 

 were propagated the preceding year, at which time they had been 

 secured from the Jamaica station. During the month of November, 

 the time of harvesting the tubers in Biloxi, the hydroc} r anic-acid con- 

 tent was studied, the determinations being made upon the freshly 

 harvested cassava at Biloxi, according to the methods of analysis pre- 

 viously described. 



The primary object of the study was to identify the sweet and the 

 bitter varieties and to ascertain their water and starch content. In 

 addition to the pedigreed plants a common Florida variety was grown, 

 which was taken from the stock in general cultivation in that State. 

 The results obtained on these tubers are given in Table III. 



