492 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



low the practice of vaccinatirtg directly from tlie cow to insure safety 

 against taking' aiiy otlier contagion with the smallpox. A new idea haa 

 been started — to drink the milk of tlie infected cow. The doctor has found 

 it effectual, and now recommends that young ladies who are afraid of the 

 lancet should drink a glass of this kind of milk every three or four years. 



Dr. Vander Weyde, formerly one of the active members of the Polytech- 

 nic, makes the following connnunication to the N. Y. Herald. 



Photography as a Detective. 



As a matter of information to your many readers, I wish to remark that 

 as the dark retina of the eye lies in the interior, and is entirely invisible, 

 so any image seen in the eye is due to the reflection of the outer surface or 

 cornea, and that when taking an enlarged photograph of it these images 

 may always be seen in the print. These are simply the images of the ob- 

 jects reflected at the time and place when and where the picture is taken. 

 1 had once the image of myself and apparatus visible in an enlarged da- 

 guerreot3'pe of a living eye, and it is indeed difficult to photograph an eye 

 at all without obtaining such reflected images. 



The human face seen in the photographed eye of the murdered woman in 

 Florence was (if really a human face), undoubtedly the image of the artist's ^ 

 own face when he took the picture. In a living eye the image is a perfect 

 likeness. In a dead eye this image is, by the collapse of the cornea, either 

 destroyed or at least distorted and inipe;fect, and caiuiot be recognized. 



Wlien we take into account all the conditions necessary to produce a 

 permanent image of any object, it appears surprising that persons are found 

 who have any laith in such a fable as that the eye of a dead person could 

 possibly contain an}^ permanent visible picture. Probably the poetry of 

 the idea strikes and pleases the imagination of many; but all belief in it is 

 destro^'ed when tested by the true philosophy of facts and experience. 



P. H. Vander Weyde, iM. D., 

 Professor of Industrial Science. 



GiRARD College, Philadelphia, Feb. 6, 1865. 



GoTTscHALK, in his " Notes of a Pianist," in the February number of the 

 Atlantic Montldy, thus discourses: 



Music as a Physical Agent. 



" It communicates to the body shocks which agitate the members to their 

 base. In churches the flame of the candles oscillates to the quake of the 

 organ. A powerful orchestra near a sheet of water ruffles its surface. A 

 learned traveler speaks of an iron ring which swings to and fro to the mur- 

 mur of the Tivoli Falls. In Switzerland I excited at will, in a poor child 

 afflicted with a frightful nervous malady, lysterical and catalyptic crises, 

 by playing in the minor key of E flat. The celebrated Doctor Bertier asserts 

 that the sound of a drum gives him the colic. Certain medical men state 

 that the notes of the trumpet quicken the pulse and induce slight perspira- 

 tion. The sound of the bassoon is cold; the notes of the Frenc'i horn at a 

 distance, and of the harp, are voluptious. The flute played softly in the 

 middle register calms the nervesl The low notes of the piano frighten 

 children. I once had a dog who would generally sleep on hearing music, 

 but the moment I played in the minor key he would ba>-k pitcously Tho 



