ALLANTOIN. 681 



the oxidation of uric acid in the animal body, yet we have no positive proof 

 of such a formation. 1 



Oxalic acid is best detected and quantitatively determined according 

 to the method suggested by SALKOWSKI : Shaking out the oxalic acid from 

 the acidified urine by means of ether. The method suggested by AUTEN- 

 RIETH and BARTH is as follows: 



The twenty-four-hour urine is precipitated by CaCl2 and ammonia 

 in excess. After 18-20 hours the precipitate is collected (the nitrate 

 must be clear) and dissolved in a little hydrochloric acid and shaken 

 out 4-5 times with 150-200 cc. ether (containing 3 per cent absolute 

 alcohol) . The united ethereal extracts are filtered through a dry filter 

 and distilled after the addition of about 5 cc. of water. The liquid, if 

 necessary, is decolorized with animal charcoal and precipitated with 

 CaCl2 and ammonia, made acid after a certain time with acetic acid, 

 and finally the oxalate is collected, washed, burned to CaO, and weighed. 

 MACLEAN 2 finds that this method yields too low results, as some calcium 

 oxalate always remains in the filtrate and the original method as suggested 

 by SALKOWSKI is more trustworthy. 



.NH.CH.HN.CO.NHa, 

 Allantoin (GLYOXYLDIUREIDE), C^eN-iOs, OC<f 



X NH.CO 



occurs in the urine of children within the first eight days after birth, and 

 in very small amounts also in the urine of adults (GUSSEROW, ZIEGLER 

 and HERMANN) . It is found in rather abundant quantities in the urine of 

 pregnant women (GUSSEROW). According to WIECHOWSKI the urine 

 of adults, if it contains any allantoin at all, has only traces, and he could 

 not detect any in the urine of nurslings or in the amniotic fluid, which 

 does not agree with previous reports. Allantoin has also been found in 

 the urine of suckling calves (WOHLER), in urine of oxen (SALKOWSKI), 

 and sometimes in the urine of other animals (MEISSNER). WIECHOWSKI 

 has found it in relatively large quantities in the urine of the dog, cat, 

 rabbit and monkey, and he considers that allantoin is a terminal metabolic 

 product in these animals. It is also found, as first shown by VAUQUELIN 

 and LASSAiGNE, 3 in the allantoic fluid of the cow (hence the name) . That 

 allantoin is formed from the uric acid in mammalia but not in human 

 beings (WIECHOWSKI) is almost certain, and the investigations on which 

 this is based have already been given in discussing the decomposition 

 of uric acid. The allantoin thus originates from the purine bodies, and 



1 See Wiener, Ergebnisse der Physiol.,*!, Abt. 1. 



2 Salkowski, Zeitschr. f. physiol. Chem., 29; Autenrieth and Earth, ibid., 35; 

 Mac Lean, ibid., GO. 



3 Ziegler and Hermann, see Gusserow, Arch, f . Gynakol, 3 both cited from Huppert- 

 Neubauer, Harn- Analyse, 10. Aufl., 377; Wohler, Annal. d. Chem. u. Pharm., 70; 

 Salkowski, Zeitschr. f. physiol. Chem., 42; Meissner, Zeitschr. f. rat. Med. (3), 31; 

 Lassaigne, Annal. de Chim. et Phys., 17; Wiechowski, Hofmeister's Beitrage, 11, and 

 Arch. f. exp. Path. u. Pharm., 60. 



