246 



chow's direction, and then independently hy His ^ and 

 Langhans," the subject of experimental studies. 



The ideas prevailing at that time were supported by a 

 number of fine observations and detailed and accurate 

 statements ; but on the whole, the view advanced by Bowman 

 was but little changed. 



Since then no remarkable experimental researches on in- 

 flammation of the cornea were published, until Reckling- 

 hausen's^ incisive essay assigned a new path to tissue- 

 pathology. 



The doctrine of the derivation of pus from the corneal 

 corpuscles was not altered by this publication, but Reckling- 

 hausen brought histological notions and methods,'^ which had 

 only just then been devised, to bear upon the department of 

 tissue pathology, and discovered the contractility and wander- 

 ing power of the pus corpuscles. 



Four years later Cohnheim'' announced that he had in- 

 vestigated the occurrences in inflammation of the cornea 

 afresh, and in the spirit of modern science and that he, with 

 the assistance of a fine reaction discovered by him, had come 

 to the conclusion that the corneal corpuscles take no share in 

 pus formation. He was able, he said, to make structural 

 elements plainly visible by chloride of gold, and in this 

 manner demonstrated that they remained quite intact, how- 

 ever numerously the pus-corpuscles were formed. 



After such a positive declaration all contrary observations 

 that had been received until that time became doubtful, and 

 so much the more when Cohnheim drew the attention of his 

 fellow-observers to the point that cell-division in the inflamed 

 tissue was in general admitted as true, but that, in reality, had 

 not been observed by anybody. 



In relation to this matter, Cohnheim pointed to the perme- 

 ability of the uninjured vascular walls ; he referred to the 

 fact that in the process of inflammation colourless corpuscles 

 really wander out, and in this way advocated the same law 

 for the cornea which Waller had advanced for the frog's 

 tongue without any success. 



Hoff'mann,^ a pupil of Recklinghausen, tried then to defend 

 tlie older idea conditionally in proving that, under certain 



' ' Beifrasj. zur norinalcn und Histologie der Cornea.' Basel, 1856. 

 2 'Zeitsclir. f. Mediciii,' 1861, 1 Uelt. 



' " Ueber Eiter-und Biadegewebskorpercben," ' Virch. Arcli.,' vol. xxviii 

 (186:5). 



■f Compare 'Haiidbuch dcr Lebre von den Gewebeu, Metbodic und Zullc.' 



® Loo. cit. 



* " Ucber Kiterbildung in dor Cornea," ' Virclunv's Arcbiv,' vol. xlii, p. 



2iH: 



