34 NOTE ON A METHOD OF PREPARING THE CORNEA. 



being filled witli numerous small otolitLic particles, -wliich 

 were in the right sac very much less numerous than in the 

 left (Plate III, fig. 15). 



Note on a Method of Preparing the Cornea. 

 By Dr. E. Klein, F.R.S. 



In his studies on inflammation, Strieker {' Medizin. Jahr- 

 biicher/ 1875) uses caustic potash as a means of producing 

 keratitis. The centre of the cornea of a kitten is touched 

 with a pointed stick of caustic potash, and after the lapse of 

 twenty-four to forty-eight hours — according to the required 

 stage of inflammation — the cornea is treated with lunar 

 caustic, and then left to stand in water acidulated with acetic 

 acid. 



Adopting this method of Strieker's, of combining the use 

 of caustic potash with that of lunar caustic in preparing the 

 cornea I obtained specimens which demonstrate the normal 

 structure of this organ in an exceedingly beautiful manner. 

 The way I followed was this : The centre of a cornea of a 

 young Idtten that had been chloralized, was touched with 

 the tip of a stick of caustic potash ; after twenty-fours hours 

 the surface of the cornea was gently rubbed with lunar 

 caustic once or twice, was excised after half an hour and 

 placed in water acidulated with acetic acid. In one or two 

 days the organ had swollen up into a thick gelatinous body, 

 from which thin lamellae were stripped oft' by means of 

 pointed forceps and finally mounted in glycerine. The 

 lamellae obtained from the anterior half of the cornea — ex- 

 cept those on the very surface — proved most instructive. 



I have before me a thin lamellae, comprising nearly the 

 whole breadth of the organ ; the preparation has been 

 mounted over a year, and all parts are as distinct and sharp 

 as ever. Without intending to describe minutely the appear- 

 ances presented by cornea prepared in the above manner, 

 with regard to the abnormal changes that had taken place in 

 the structural elements of the organ — this subject I hope to 

 discuss at another time in a special memoir — I will mention 

 here, that the outlines of the lymph-canal system and of the 

 corneal corpuscles lining this are very indistinct in the centre 

 of the cornea, this part having become destroyed more or 

 less. 



By gradual transitions we are brought into an annular region 



