Conjunctivitis With Mustard Oil 



509 



and smaller arterioles, and he found that if the ophthalmic nerve 

 was cut before applying mustard oil oedema could then be pro- 

 duced only during the period in which the vasodilator fibers were 

 still undegenerated, and a sufficient time were allowed for the 

 vasodilator nerves to degenerate completely before the mustard 

 oil was applied, oedema did not result after the instillation of 

 mustard oil. Bruce's results have been confirmed by Bardy. 1 



In 1917 I 2 was able to demonstrate the following facts: (1) 

 That the application of epinephrin, producing a local vaso con- 

 striction of the conjunctival vessels, inhibited the development of 

 the oedema, for about an hour, but that after the epinephrin 

 effect had worn off oedema developed subsequently. (2) That 

 any continued lowering of the general blood pressure to less 

 than 50 mm. Hg. prevented or greatly retarded the development 

 of the oedema, even if the conjunctival vessels were dilated by 

 the local administration of 1 per cent, sodium nitrite or if lymph 

 secretion were increased by the intravenous injection of "Witte's 

 peptone." (3) That intravenous lowering of the general blood 

 pressure by the continuous intravenous injection of dilute hydro- 

 chloric acid, in spite of the acidosis produced, diminished or en- 

 tirely prevented the development of the oedema from mustard 

 oil. (4) That ligation of the carotid artery greatly reduced the 

 development of oedema in the eye upon the side corresponding 

 to the ligated artery; and that in the peripheral end of the ligated 

 artery the blood pressure was less than 40 mm. Hg. 



These experiments would lead to the conclusion that the 

 oedema develops only when there is a sufficiently high pressure 

 in the arterioles and capillaries to bring about a sufficient filtra- 

 tion after the walls of the blood vessels have been injured; and 

 that if an adequate pressure is not present, the oedema does not 

 develop whether the smaller vessels are dilated or not. 



Since Krogh 3 ' 4 in his studies upon the capillary circulation 

 lays a great deal of emphasis on the functional importance of 

 axon reflexes and upon Ninian Bruce's studies, it seemed of in- 

 terest to determine the effect that local anaesthetics other than 



1 Bardy, H., SJsand. Arch. f. Physiol, 1914-15, xxxii, 198. 



2 Hirschf elder, A. D., Jour. A. M. A., 1916, lxvii, 1891; and Trans. Sec. 

 Pharmacol, and Therap. A. M. A., 1917, 182. 



3 Krogh, A., Jour. Physiol., 1919-1920, liii, 398; 1921, Iv, 412. 



4 Krogh, A., Harrop, G. A., and Rehberg, P. B., Ibid, 1922, lvi, 179. 



