245 



this change. First, Goodsir and Redfern announced the 

 "Towth and multiplication of cells in diseased cartilage. 

 Virchow joined them, basing his support on his researches on 

 connective issue. 



In the followinnf ten years, even up till 1860, observations in 

 this province were nearly all carried out in the light of 

 Virchow's doctrine, until Cohnheim,^ in the year 1867, in a 

 better position for making an attack than Waller, took up 

 again the old idea of deriving the pus corpuscles from the 

 blood. 



Shortly before this I had introduced a method ^ which has 

 become very important in this matter — -that method, I mean, of 

 bringing curarised animals under the microscope, and of 

 examining the circulatory vessels, and the circulating blood 

 itself, under high magnifying powers. In this way I could 

 observe with leisure the vascular walls perforated by the blood- 

 corpuscles, and so obtain a diagnosis which was beyond doubt. 



('ohnheim has now taken up Waller's forgotten experiments, 

 also by the use of curarised animals. He has recognised the 

 exodus of blood-corpuscles in great masses as a constant 

 occurrence, and has obtained for the theory founded upon this 

 observation a recognition which it had never enjoyed before. 



History of Experiments on Keratitis Traumatica. 



As far as modern tissue-pathology is concerned, Bowman ^ 

 was the first Avho brought the cornea into the domain of 

 experiment. Whilst formerly the transparent organs only 

 had served to ascertain, by experiments, the occurrences at the 

 the blood-vessels, we find in Bowman, in accordance with 

 Redfern,^ the nutritional disturbances put into the fore- 

 ground. " If we puncture or incise the cornea, the first 

 effect is a change wrought in the natural actions of nutrition 

 then existing in the wounded parts." With these words 

 Bowman introduces his studies on keratitis traumatica, and 

 explains, in an unmistakble way, that near tlie injured place 

 the corneal corpuscles, which he still calls " nuclei or cyto- 

 blasts," multiplicand that these embryonal structures mixed 

 up with old ones cause the milky dimness of the cornea. 



The cornea has since been made by Strube,^ under Vir- 



^ "Ueber Entziindunsc and Eiterung," 'Virchow's Arcliiv,' 18G7, vol. xi. 



- ' Sitzungsberichie,' lii, 18G5. 



^ ' Lectures on the Parts concerned in 0])erations on the Eye,' p. 29. 

 London, 184:9. 



•* Loc. cit. 



* 'Der normale Ban der Cornea und die pathologischen Abweichuugen in 

 derseiben.' Inaug. Diss. Wiirzburg, 1854. 



