10 



MISCELLANEOUS PAPERS. 



portion and the latter the seed of Opuntia pliaeacantha. The fleshy- 

 portion contained 25.60 per cent of ash, while the seed contained only 

 1.77 per cent. 



The elements of the ash are present in about the same proportion as 

 in the ash of other plants, except potassium, magnesium, and calcium, 

 which are found in large amounts. It is probably the presence of 

 these salts, coupled with the high water content, that causes cattle to 

 scour when fed on an exclusive roughage ration of these j)lants. 



In the following table there is given a complete analysis of the ash 

 of a few of the samples, together with the results of the analysis of a 

 composite sample, and an average of all the ash analyses made. Com- 

 plete ash analyses were made of 26 samples besides the composite, 

 w^hich was a mixture prepared by carefully igniting in a muffle two 

 grams of the ash of each of the 187 samples of cactus analyzed. 



Table I. — Chemical analyses of representative samples of cacti. 



102—1 



a For explanation of formula, see page 6. 



