Bailliart,1inventor of the so-called mo-ophthalmodynamometer, a practical and important instrument, on examining with Magitot and other collaborators the pressure in the central artery of the retina in different diseases of the eye, ascertained an increase of the pressure in this artery to which no increase in other arteries of the body corresponded. The studies of Professor Espíldora-Luque,2of the clinic for ocular diseases, University of Chile, Santiago, refer to the same increase, which he verified in his own patients. The reduction scale of Müller, Brüning and Mohr represents an improvement on that of Bailliart. It serves to reduce the numbers in grams of the dynamometer to millimeters (mercury). The mentioned authors based their scale on observations of the human eye which gave them much smaller intervals than those of Bailliart's scale, who drew his values from the study of the eyes of cats. While Bailliart's apparatus records