747 
Facts and Observations. 
Influence of Magnets on Animals. — In the April 
number of the American Psychological Journal there is an ex- 
tremely interesting paper by Dr. John Vansant, describing 
the results of several curious experiments with magnets on 
animals and plants. Dr. Vansant's attention was first par- 
ticularly directed to the subject of this communication in 
the winter of 1866, when he observed that a small magnetized 
steel rod, the ends of which were finely pointed, if brought 
carefully in contact with an exquisitely sensitive blister, that 
had been accidentally produced on one of his fingers by 
pinching it, gave rise, when the southward pole was applied 
to a momentary sharp sensation, and seemed to cause the 
blister to be more painful after the magnet was removed. 
When the northward pole was used in the same way, no 
sensation could be felt at the moment of contact, and after 
removal the original pain remarkably subsided. Struck by 
this phenomenon, and yet almost doubting his own sensa- 
tions, he proceeded to inquire if it were possible to recognise 
a difference between the two ends of the magnet by means 
of some organ peculiarly sensitive in its normal condition. 
On trial, he found that the conjunctival membrane of the 
eye would indicate by the feeling which pole it was touched 
with. He could lay with care the sharpened northward end 
of the magnetic rod on that membrane without pain or wink- 
ing; but the instant the southward pole w r as applied, no matter 
w ith how much delicacy, there was a sharp sensation and an 
involuntary slight closing of the eyelid. The effect was 
faint, but plain. This experiment was repeated on the eye 
of another person, the same day, wuth similar results. After 
this he made numerous experiments with magnets of different 
forms and powers (though not at any time with very large 
ones) applied to various parts of the body, and thought he 
observed a definite set of symptoms arise after every applica- 
tion in the same manner to a given part, provided sufficient 
time had elapsed between the applications. The author then 
details several curious experiments, wffiich some of our readers 
would do well to repeat. — Popular Science Review. 
A New Theory of Nervous Sensation. — The Che- 
mical News gives a report of a recent meeting of the 
Royal Irish Academy at which a paper was read by Dr. 
Robert M ‘Donnell on the above subject. The author's paper 
might be briefly described as an application of a theory 
similar to the wave theory of light to the propagation of 
sensation along the nerves. He compared this “ undulatory” 
