H 



Journal of Agricultural Research 



Vol. XXII, No. I 



The nature of the possible toxicity of the velvet bean has been recently 

 suggested by Miller * to be due to dihydroxypehnylalanine. 



Cooking the seed at 15 pounds pressure for one hour destroyed for 

 the most part its harmful effects, but there was still some injury when 

 fed cooked at as high a plane of intake as 80 per cent. When 80 per cent 

 of the velvet bean served as a source of protein, little growth resulted, 

 nor was there a response obtained after 9 per cent of the seed was replaced 

 by 9 per cent of casein, although when only 40 per cent velvet bean was 

 served as a source of protein, supplemented with the same amount of 

 casein, excellent growth was obtained. Unpublished data in this labo- 

 ratory show that the better growth on the lower level of seed intake is 

 not to be attributed to the higher intake of dextrin. Additional evidence 

 is apparent from the fat-soluble vitamin experiment that when cooked 



Gn 



/GO 



/20 



/OO 



So 

 60 



Fig. 15. — Gain in weight of lot 86 on ration of velvet beans (uncooked) 40 per cent; butter fat, 5 per 

 cent; No. 32 salts, 4 per cent; casein, 9 per cent; and dextrid, 42 per cent. At point x 10 per cent dex- 

 trin was replaced by 10 per cent of an alcoholic extract of ether-extracted wheat embryo. 



velvet beans are fed at an 80 per cent level some injury is still produced. 

 Reduction of the plane of intake from 80 to 40 per cent results in con- 

 siderable improvement in growth. 



That the velvet bean seed is very rich in the fat-soluble vitamin is 

 evident from the fact that normal growth was obtained for a period of 

 over five months when only 20 per cent of the seed served as the source 

 of this syndrome. Reduction of the plane of velvet-bean intake to 10 

 per cent resulted in inferior growth. The fact that considerably inferior 

 growth was obtained on lower levels of seed intake with larger amounts 

 of casein and dextiin precludes, we believe, the possibility that our 

 casein and dextrin might have furnished appreciable amounts of the 

 fat-soluble vitamin at the higher levels of seed intake, where we had 

 remarkable success. It is also apparent from these experiments that 

 autoclaving the seed for one hour at 15 pounds pressure has no deleterious 

 effect on the fat-soluble vitamin. 



1 Miller, Emerson R. DrHVDRoxYPHENYLALANiNe, a constituent of the velvet bean. 

 Biol. Chem., v. 44, no. 2, p. 481-486. 1920. 



In Jour. 



