10 



distal part of the optic nerve (that left in connexion with the eye- 

 ball), examined after the lapse of a month in one case, and of two 

 months in another, was also discovered to be unaltered. On the 

 other hand, the part of the nerve behind or on the central side of 

 the section was invariably disorganized. The section was usually 

 performed on the optic nerve of the right eye, and the disorganized 

 fibres of its central segment could be traced back to the left optic 

 tract, through the chiasma, where they obviously decussated with 

 the sound fibres of the opposite nerve. The right optic tract had 

 undergone no change ; the fibres of the left tract were disorganized 

 as far back as the quadrigeminate bodies, except those running along 

 the posterior or inner border of the tract ; which exception appears 

 to the author to favour the opinion that fibres pass along the tracts 

 and commissures from the quadrigeminate bodies of one side to those 

 of the other side, without connecting themselves with the retina. 

 On the other hand, the results of his experiments do not seem to 

 him to countenance the notion of fibres running in the optic nerves 

 from one retina to the other without connexion with the brain, nor 

 the generally received doctrine that part of the fibres of the optic 

 nerve are continuous with the optic tract of the same side ; on the 

 contrary, the whole fibres of the nerve would seem to undergo decus- 

 sation. 



The microscopic characters of the atrophied and disorganized 

 nervous substance are described in the paper ; they were found to 

 differ somewhat in the part of the nerve before and that behind the 

 chiasma, owing no doubt to the different structure of these parts in 

 the sound state. 



The changes produced in the geniculate and quadrigeminal bodies 

 will be communicated in the succeeding part of the paper. 



II. ' On some of the Metamorphoses of Naphthalamine." By 

 A. W. HOFMANN, Ph.D., F.E.S. &c. Received January 

 10, 1856. 



The great facility with which some of the nitro-hydrocarbons can 

 be reduced by means of iron and acetic acid the modification of 

 Zinin's process, lately proposed by M. Bechamp enables us to 



