May 3, 1888] 



NATURE 



15 



It will be convenient to reproduce Dr. Venn's figures in 

 a separate table, neglecting the second decimal : — 



Head Products. 



The figures in the table are thrown into diagrams in 

 Figs. I., II., and III., in which curves are also drawn to 

 interpret what seems to be their significance. The great 



irregularity in Fig. II., corresponding to the age of twenty- 

 four, may be fairly ascribed to the smallness of observa- 

 tions, only thirteen in number, on which it is founded. 

 The three resultant curves are shown by themselves in 

 Fig. IV., where they can be easily compared. It will then 

 be seen that the A and C curves are markedly different, 

 and that the B curve is intermediate. Accepting these 

 curves as a true statement of the case — and they are 

 beyond doubt an approximately true statement— we find 

 that a " high honour " man possesses at the age of nine- 

 teen a distinctly larger brain than a " poll " man in the 

 proportion of 241 to 230-5, or one that is almost 5 

 per cent, larger. By the end of his College career, the 

 brain of the " high honour" man has increased from 241 

 to 249 ; that is by 3 per cent, of its size, while the brain 

 of the " poll " man has increased from 230-5 to 2445, or 

 6 per cent. 



Four conclusions follow from all this : — 



(1) Although it is pretty well ascertained that in'the 

 masses of the population the brain ceases to grow after 

 the age of nineteen, or even earlier, it is by no means so 

 with University students. 



(2) That men who obtain high honours have had con- 

 siderably larger brains than others at the age of nineteen. 



(3) That they have larger brains than others, but not to 



Length x Breadth x Height of Head, in inches, of Cambridge University Men at different Ages {from Dr. Venn's Tabes). 



AGES 



240 

 I 



TL 



250 240 



L 



nr 



250 230 



IV 



240 

 _J 



250 



19 



20 



21 



22- 



23- 



24- 



25 AND ) 

 UPWARDS i 



1 T 1 vj , r-! j , --1 j r 



A, First Class Men ; B, Honour Men, not First Class ; C, Poll Men. 



the same extent, at the age of twenty-five ; in fact their 

 predominance is by that time diminished to one-half of 

 what it was. 



(4) Consequently " high honour " men are presumably, 

 as a class, both more precocious and more gifted through- 

 out than others. We must therefore look upon eminent 

 University success as a fortunate combination of these 

 two helpful conditions. 



PHOTOGRAPH OF THE EYE BY FLASH OF 

 MAGNESLUM. 



THE effect of complete obscurity on the normal pupil 

 -*- has hitherto been seen only by the light of electric 

 discharges, which allowed of no measurements. 



MM. Miethe and Gaedicke, by their invention of the 

 well-known explosive magnesium mixture, have furnished 

 us with a simpler method. A photograph of the eye can 

 be taken in a perfectly dark room, showing the pupil 

 fully dilated, as its reaction does not begin until after 

 exposure. 



Mr. Miethe, astronomer at the Potsdam Observatory, 

 himself at my suggestion undertook to execute the accom- 

 panying photograph of a normal eye, life-size, after a 

 quarter of an hour's rest in a carefully darkened room. 

 The pupil was found to measure 10 mm. horizontally (the 



breadth of the cornea being 13 mm.). A reflection of 

 the flash is seen on the cornea. 



This kind of photography may prove a new and 

 valuable method for many other branches of scientific 



research, but it is of especial utility to ophthalmology, as 

 the eye, by its mobility and sensitiveness, has hitherto 

 been a most difficult subject for the camera. 



Claude du Bois-Rkymont^ 



