33 



40 C., making one slightly colder than the other. Now 

 find the smallest difference of temperature which can be 

 appreciated (a) with the tubes on the side of the face, (6) with 

 the tubes on the back of the forearm. 



///. TASTE. 



la the Sensibility to Taste the same all over the Tongue ? 



METHOD. Solutions of (1) Sugar, 



(2) Quinine, 



(3) Hydrochloric Acid, 



(4) Common Salt, 



are given you. One student rinses out the mouth with water, 

 and another applies, with a camel's-hair brush, one or other 

 of the solutions to some part of the tongue and notes the 

 sensation which is said to be produced. The mouth is again 

 rinsed and the process repeated, and thus the various parts 

 of the tongue are investigated for their sensibility to the 

 different substances. The results should be recorded as a 

 diagram. 



Cocaine may be painted upon the tongue and the tactile 

 and gustatory responses studied. 



IV. VISION. 



A. Structure. 

 I. Ox Eye out of Formalin. 



Examine the eye. Identify the cornea and sclerotic, and 

 notice the entrance of the optic nerve to the inner side of 

 the posterior axis. Note the shape of the pupil. Now divide 

 the eye into an anterior and a posterior half by cutting through 

 the equator of the sclerotic with a sharp razor. 



Note the gelatinous vitreous humour in the posterior 

 chamber. Note the black-coloured choroid coat inside the 

 sclerotic. In the anterior segment note that the capsule of the 



