656 VERHOEFF AND BELL. 



days. Marked keratitis and abiotic changes in lens epithelium. 

 Retina normal. 



With flint glass screen (298 hijl) : 



Experiment 78. (PI. 4, Fig. 11). Exposed 1 hour. After 20 

 minutes: Cornea shows well marked central haze (heat effect). 

 Epithelium intact. After 24 hours: Slight conjunctival reaction. 

 Haze of cornea greater. Central loss of epithelium (5 mm.). After 

 72 hours: Corneal epithelium reformed. Haze of stroma persists. 

 Enucleation. Eye immediately opened. Fundus bisected vertically. 

 One half fixed in saturated solution of mercuric chloride. The other 

 stained by the vital methylene blue method. Lens fixed in Zenker's 

 fluid. Microscopic examination : Corneal stroma swollen to 3 normal 

 thickness. Corneal corpuscles completely destroyed in posterior 

 two-thirds, present, but show characteristic abiotic changes in anterior 

 third. Endotheliimi necrotic and absent in places. Lens epithelium 

 shows marked abiotic changes. Retina normal. 



mth crown glass screen (300 /zyu) : 



Experiment 79. Exposed 1 hour. Slight conjunctival reaction. 

 Marked central haze of cornea with loss of epithelium. ^Microscopic 

 examination (48 hrs.): Corneal stroma swollen to twice normal thick- 

 ness. Epithelium, corneal corpuscles, and endothelium completely 

 destroyed in central area. Towards the periphery corpuscles first 

 show abiotic changes then proliferative changes (heat effect). Lens 

 epithelium shows slight but definite abiotic changes — swelling of 

 cells and characteristic granules. Iris normal (unexposed). Retina 

 normal. 



Experiment 80. Exposed 20 minutes. Slight central haze of cornea 

 persisting over 9 days. Epithelium intact. 



With flint glass screen (305 nn): 



Experiment 81. (PI. 1, Fig. 2). Exposed 1 hour. Immedi- 

 ately after exposure ; cornea perfectly clear. After one hour : Cornea 

 shows distinct central haze. After 24 hours: Cornea more hazy, 

 epithelium intact and normal. After 3 days: Haze of cornea persists. 

 There has been no loss of epithelium on daily examination. Micro- 

 scopic examination (3 days) : Corneal epithelium intact. Stroma 

 swollen to § normal thickness. Endothelium absent. Corpuscles 

 invisible in posterior \ of exposed area, present and actively proliferat- 

 ing in anterior portion. No evidences of abiotic action. (Iris not 

 exposed). Lens epithelium normal. Retina normal. 



Experiment 82. Exposed 1| hours. Immediately after exposure: 

 cornea shows faint haze. After 45 minutes: Corneal haze more 



