428 THE METABOLISM OF THE PURIN BODIES 



amount of uric acid is contained in the urine of leucocythaemic 

 patients ( 20 ). Some years later (in 1889) Horbaczewski ( 5 ), after 

 showing that by blowing air through a mixture of spleen pulp 

 and blood uric acid is formed, brought forward the hypothesis 

 that all the uric acid in the urine is derived from the nuclein 

 of leucocytes. According to this view even nuclein-containing 

 food increases the excretion only because it induces an increased 

 leucolysis. 



To prove this hypothesis, Horbaczewski made estimations of the 

 number of leucocytes per cubic millimetre of blood removed from 

 a peripheral vessel, and compared this result with the two-hourly 

 uric acid excretion. He found them to run parallel. Where 

 leucocytosis (increased number of leucocytes) existed there was 

 increased uric acid excretion (e.g. in children, during the absorp- 

 tion of food, after the administration of pilocarpine, &c.); where, 

 on the other hand, the number of leucocytes was subnormal there 

 was a subnormal uric acid excretion (after quinine and atropin). 

 He considered his doctrine confirmed by numerous clinical observa- 

 tions in which a high purin excretion was associated with a 

 peripheral leucocytosis. Even where extreme and acute tissue 

 disintegration existed, as in inanition and phosphorus poisoning, 

 and a hyper-excretion of purins was present, none of the latter 

 was supposed to come from the nuclein of the tissue cells, but all 

 of it from leucocytic decay induced, according to Horbaczewski, 

 by the liberated tissue nucleins. The liberated tissue nucleins 

 acted as stimulants of leucocytic disintegration. 



This hypothesis was accepted as correct by nearly all workers. 

 Even where the number of leucocytes per cubic millimetre of 

 blood did not run parallel with the uric acid excretion ; even 

 although some observers found no increase in the latter in marked 

 cases of leucocythsemia, and others a normal uric acid excretion 

 where the leucocytes were much diminished in amount, no one 

 doubted the truth of the hypothesis. By the exercise of a vivid 

 imagination it was possible to explain away all difficulties : if the 

 uric acid excretion were normal, but the leucocytes increased in 

 the blood of a peripheral vessel, the increase of the latter must 

 be entirely due to increased production, their destruction remain- 

 ing constant ; the former process must have been more active for 

 some time and the destructive forces not able to keep down the 

 level. 



