Medical Apparatuses 431 



rabbit in regard to changes in the circulation in the ears and the 

 conjunctiva. I copy the details which he gave on this subject, 

 because they do not seem to me to justify the conclusions which 

 he drew from them and which were accepted on his authority. 



I. (a). Normal pressure: 



The rabbit quiet and free. The ears erect, swollen with blood. 

 The vessels of the conjunctiva congested. The iris and particularly 

 the pupil very red. 



(b). During the increase of pressure: 



Vessels of the conjunctiva thinner and paler. Loss of. color in the 

 iris and the pupil. 



(c). During the constant maximum pressure: 



By transparency, the vessels of the ears empty of blood; the 

 largest are hardly visible; shortly after, the ear is quite pale and limp 

 and the vessels have completely disappeared, 

 (d). During the decrease of pressure: 



The ear and the conjunctiva remain pale. 



(e). Under normal pressure, immediately after treatment: 



After the treatment, even an hour after, the ears are empty of 

 blood, pale and limp. 



II. (a). The vessels- of the ears are moderately congested. 



(b). At the beginning, a greater congestion of the arteries and 

 the veins of the ear; later the iris first grows pale and then loses its 

 color. 



(c). The ears remain pale; the iris is darker; the pupil redder. 



III. (a). The vessels of the ears are moderately congested; the 

 iris and the pupil are a beautiful red. 



(b). Swelling of the vessels and particularly of the veins of 

 the ears, the largest of which are dilated. 



(c). At the beginning, no change noticeable in the color of 

 the iris and the pupil. The vessels of the ear alternately grow pale 

 suddenly and fill up again; however, some time afterward, they are 

 definitely pale and remain empty of blood, 

 (d). The ears are still pale and limp. 



(e). Some hours after the treatment, the ears are still quite 

 empty of blood, pale, and limp. 



IV. (a). Long before the treatment, the ears are rather empty of 

 blood. 



(b). The vessels of the ears are alternately congested and pale; 

 finally they remain pale. 



(c). Because of the darkness in the apparatus, the color of the 

 pupil cannot be observed. 



(d). The ears still pale. 



(e). The pupil seems to become dark red. The ears are well 

 filled with blood. 



V. (a). The conjunctiva congested at isolated places. The vessels 

 of the ear moderately congested. 



(b). The congestion of the conjunctiva and the vessels of the 

 ear partly disappears. 



