Conjunctivitis and Mustard Oil 



511 



cocaine might produce upon the development of oedema from 

 mustard oil. We tested the effects of instilling the following 

 solutions upon the development of mustard oil conjunctival 

 oedema: (1)4 per cent, cocaine solution in 0.9 per cent. NaCl; 

 (2) 4 per cent, procaine (novocaine) in 0.9 per cent. NaCl; (3) 

 4 per cent, saligenin in 0.9 per cent. NaCl; and (4) 2 per cent, 

 butyn 



/\NH 2 

 I I 



\/COOCH 2 CH 2 CH 2 N(C 4 H 9 ) 2 , sulphate 

 dissolved in distilled water. 



These substances produced complete sensory anaesthesia of 

 the conjunctiva so that the corneal conjunctiva would be 

 scratched with a thin copper wire without causing any winking 

 reflex or any other movements of the rabbit. 



Procaine and butyn seem to have no marked effect on blood 

 vessels; saligenin definitely dilates them. 



It will be seen that the oedema developed in the same manner 

 and degree and with the same rapidity in the anaesthetized as 

 in the unanaesthetized eye, in all the experiments with the excep- 

 tion of one in which the oil was instilled almost immediately 

 after the 4 per cent, cocaine. This exception may be due to some 

 vaso constrictor action of the cocaine. 



These experiments seem to indicate that mere sensory an- 

 aesthesia does not prevent or inhibit the development of oedema 

 from mustard oil, and that the maintenance of a high filtration 

 pressure in the vessels of the eyelid is the most important factor 

 in the development of oedema in an area, the walls of whose 

 blood vessels have been injured by this agent. 



It is possible that in Bruce's employment of 10 per cent, alypine 

 and 10 per cent, cocaine to inhibit the oedema, the hypertonic 

 solution of the drug acted to constrict the vessels; and' that, 

 in his experiments on cutting the ophthalmic nerves, the still 

 intact vasoconstrictor fibers may have brought about a pre- 

 dominant constrictor response after the vasodilator nerves had 

 degenerated. 



