SOME FRUITS OF HAWAII 



107 



Total asli 



The ash content of the fruit is the residue which remains after 

 burning the substance until it is free from carbon. 



In most cases the material was ashed in the fresh state. Each 

 sample was weighed directly into a weighed silica dish containing a 

 piece of ashless filter paper, which protects the bottom of the dish 

 from the action of acid and minerals. 



Aliquots of the solution of the ash were used for the determination 

 of calcium and phosphorus in every case and for iron in those cases 

 in which the method of preparation of the sample precluded iron con- 

 tamination. 



Calcium 



The calcium content of the fruit was determined by a slight modifi- 

 cation of the McCrudden volumetric method (61). 



Phosphorus 



To determine the phosphorus content of the fruit the ammonium 

 phosphomolybdate volumetric method was used. 



Iron 



The iron content of the fruit was determined by the method of 

 Elvehjem and Hart (13). A blank was run with each group of analy- 

 ses, and the iron found in the blank was subtracted from the total iron 

 found in the fruit. The samples were ashed in a closed electric muffle, 

 without previous drying, and every care was taken to prevent any iron 

 contamination. 



Methods of vitamin determinations 



All experimental animals were raised in the station laboratory. The 

 mothers of all experimental rats received the following diet : whole 

 wheat 960 grams, whole milk powder 400 grams, cooked soybean meal 

 100 grams, dried yeast 65 grams, wheat germ 40 grams, sodium chloride 

 10 grams, salt mixture 10 grams. The salt mixture was made up of 

 9 parts calcium carbonate and 1 part ferric citrate. 



All experimental animals were kept in individual cages with raised 

 screen bottoms, and were allowed distilled water and the basal diets 

 ad libitum. 



Unless otherwise noted, the fruits were prepared for feeding in the 

 same manner as for analysis. Pohas were used fresh and not dried. 

 The fruits were not finely chopped or mashed as for the analyses but 

 representative samples of such fruits as papayas, figs and pohas were 

 always taken. 



Vitamin A: For the vitamin A experiments, young rats were 

 weaned at about 3 weeks of age and placed on the following experi- 

 mental diet: extracted casein (62, p. 257) 18 percent, dried yeast 

 (Northwestern) 10 percent, salt mixture (42) 4 percent, sodium chlo- 



