670 



SUBJECT INDEX 



Phosphotungstic acid, 248 

 Photopsins, 61, 82 

 Photosynthesis, 220 

 Phrynoderma, 152 

 Phthalylsulfathiazole, 603 

 "Physin", 



identification of, 514 

 Pigs, see Swine 

 Pimelic acid, 562, 589, 595 



analogs, 



as inhibitors, 571 



biotin-activity of, 564, 586 

 Pining, 521 

 Plants, 



effect of ascorbic acid on, 306-309 

 Plasmodium, 



biotin and, 611-612 

 Platelets, 



in scurvy, 292 

 Polarography, 



in ascorbic acid assay, 257-258 

 Poliomyelitis, 



biotin and, 611 

 Polyhydroxyphenols, 226 

 Polyphenolase, 226 

 Polyphenoloxidase, 225 



in ascorbic acid oxidation, 226-227 

 Porphyropsin, 66 



nature of, 59, 61 

 Potassium, 373 



in scurvy, 365 



relation to biotin, 603 

 Potassium bichromate, 



as color standard, 88 

 Potassium ferricyanide, 248 

 Poteriochromonas stipUata, 



in vitamin B12 assay, 460-461 

 Procollagen fibers, 



in scurvy, 278 

 Pregnancy, 



ascorbic acid requirement in, 386, 390 

 Pro -7 -carotene, 86 

 Progesterone, 



avidin and, 608-609 

 Propionic acid, 



biotin and, 584 

 Protein, 



in carotene transport, 83-84 



requirement in pernicious anemia, 500- 

 501 



tumors and, 610 



vitamin B12 and, 444, 507, 515 

 Prothrombin, 292, 327, 375, 376 



in hypervitaminosis A, 124 



in pernicious anemia, 501 



in scurvjs 293 

 Protogen, 457 

 Protoplasm, 



effect of ascorbic acid on, 302-303 

 Protoporphyrin, 370 

 Provitamins A, 87, see also Carotenoids 



assay of, 92-95 



conversion to vitamin A, 103 

 Pseudoionone, 42 

 Pseudoperoxidases, 226 

 Pseudovitamin B12 , 447 



microbiological activity of, 486-487 



relation to vitamin B 12, 410 



in vitamin B12 assay, 460 

 Pterin, 402 



Pteroylglutamic acid, see Folic acid 

 Purines, 



formate and, 429-430 

 Purpura, 353, 359 



causes of, 375 

 Pyocyanin, 236 



Pyrazolone-pyridine reagent, 450, 452 

 Pyridoxamine phosphate, 



requirement for, 456 

 Pyridoxine, 117, 457 

 Pyrroles, 



in vitamin B 12 , 402 

 Pyruvic acid, 66, 69, 214, 223, 229, 279, 

 333, 334, 583 



ascorbic acid and, 214, 215, 329 



in aspartic acid synthesis, 576-577 



formation from serine, 582 



metabolism in biotin deficiency, 579, 

 581 



in oxalacetic acid formation, 577 



oxidation of, 576 



vitamin B12 and, 484-485 



Quinones, 



in ascorbic acid oxidation, 225 

 Quinoxaline, 537-538 



R 



Rabbits, 

 vitamin A requirements of, 166 



