458 SCIENCE PROGRESS 



Further, the action of the animal tissue upon meso tartaric acid 

 can be explained in the following way. Laevo tartaric acid is 

 made up of two radicles, — CH(OH)COOH, each of which is 

 arranged in laevo configuration, which is favourable to the 

 attack of the organism ; dextro tartaric acid, being composed 

 oftwodextro radicles, — CH(OH)COOH, offers no foothold to 

 the destructive action of the tissues : the meso form, being made 

 up of one dextro and one laevo radicle, offers a point of attack 

 in the latter, and is therefore destroyed. 



Neuberg and his collaborators have studied that part of the 

 subject, and have examined several cases of the behaviour of 

 optical antipodes in the animal body. We may take the case 

 of the three arabinoses and their derivatives 1 as an example. 

 The arabinoses are sugars which have the structural formula 

 CH 2 OH . CH(OH) . CH(OH) . CH(OH) . CHO. The figures 

 below represent in each case the percentage of substance 

 recovered from the urine of rabbits ; column I shows the results 

 obtained when the substance was introduced through the mouth, 

 II when introduced subcutaneously, and III intravenously: 



I II III 



Laevo arabinose .... 14*5 yi 283 



Racemic arabinose . . . 28^5 317 29/0 



Dextro arabinose . . . 31*2 36*0 310 



These results agree fairly well among themselves, when allow- 

 ance is made for inevitable experimental differences. The three 

 sodium salts of the arabonic acids, CH 2 OH . CHOH . CHOH . 

 CHOH . COONa, show similar differences, though less of the 

 laevo than of the dextro isomer is attacked in their case. When 

 the corresponding alcohol arabite, CH 2 OH . CHOH . CHOH . 

 CHOH.CH 2 OH, was supplied to the animal, small quantities 

 of pentoses, CH 2 OH . CHOH . CHOH . CHOH . CHO, appeared 

 in the urine, one of the — CH 2 OH groups at the end of the 

 chain being oxidised to —CHO. 



A very important result was obtained by Neuberg and 

 Wohlgemuth 2 in the case of the human subject. In certain 

 diseases it is found that racemic arabinose makes its appearance. 

 Now, when racemic arabinose was supplied to a human subject 

 it was found that a considerable action took place, about two- 



1 Neuberg and Wohlgemuth, Ber. % 34, 1745 (1901) ; Zeit. physiol. Chem., 35, 41 

 (1902). 



2 Ibid. 



