— 174 — 



were found to be still smaller. These were determined at 

 0,0105, 0,004 and 0,035 and amounted therefore on an 

 average to 0,006°/ , while the lowest average was with 

 quite polished rice (sikat) from which resp. 0,01, 0,0025 and 

 0.004°/ P 2 5 had passed into the steaming water. 



Without going into explanations as to the comparatively 

 great differences which the estimations showed with regard 

 to the same kind of rice, apparently steamed in exactly 

 the same manner, it can be decided that the decrease in 

 the P 2 5 content in consequence of the steaming-process 

 is not worth mentioning. It is also certain that it 

 cannot be brought into comparison with the unavoidable 

 lessening of prophylactic activity which must be taken for 

 granted under a comparatively long exposure of the rice to 

 damp heat — an argument which forms one of the a priori 

 objections to the standard fixed for the P 2 5 content as 

 necessary for assuring the desired effect. 



4 th . The P 2 5 Content of the Rice is in Reality no reliable 

 Indicator for its physiological Activity. 



As long as the effective ingredients of the silver-skin of 

 the rice are unknown, and are neither to be quantatively 

 separated or be directly determined in any other manner, 

 we are obliged to have recourse to little nsed indirect methods 

 in order to obtain a chemical value-estimation. We take 

 then as standard the quantity of one or more by-constituents, 

 which are quantitavely sufficiently parallel with the effective 

 substances and can be accurately determined on chemical way. 



In the P 2 5 content of the silver-skin, which is higher 

 than that of the kernel of the rice grain, Henry Fbaseb 

 and A. T. Stanton supposed they had found the means of 

 estimating the quantity of that silver-skin in rice, and indirectly 

 at the same time to fix the degree of activity thereof. 

 In their work entitled: "The Etiology of Beri-Beri" (1911) 

 the P 2 5 amount was recommended as indicator, and they 

 also declared that for rice of good quality, affording sufficient 

 protection against beri-beri, a minimum P 2 5 amount of 0,4%— 



