SCIENTIFIC SUMMARY. 
317 
experiments on the resistance of full-sized ships, and memorialised the 
Admiralty to afford the use of one of Her Majesty’s vessels for the purposes 
of the experiments. Mr. Froude had previously applied to the Admiralty 
for assistance to carry out experiments on small models of ships on a plan 
which will, in his opinion, afford trustworthy data for calculating the re- 
sistance and for determining the proper form of ships. The Admiralty 
have decided to adopt Mr. Froude’s proposal. It is to be hoped, however, 
that some experiments on the resistance of actual ships will not be long 
postponed. Valuable as Mr. Froude’s experiments will undoubtedly be, 
naval architects and engineers require the data which would be derived 
from full-scale experiments in addition. 
Victoria Stone. — Engineering for May 23 describes a new artificial stone 
which is being manufactured near Victoria Park, by a process perfected by 
the Rev. H. Highton. The process consists of mixing broken granite, the 
refuse of the granite quarries, with hydraulic cement, and steeping the mass 
in silicate of soda. The most novel part of the process is in the way in 
which the silicate of soda is applied. The concrete masses which are to be 
silicified are immersed in a tank of silicate of soda, in which are placed 
pieces of a siliceous stone obtained at Farnham, which has the peculiarity 
that the silica is in such a state that it dissolves in cold caustic soda. The 
lime of the concrete mass takes silica from the silicate, and the soda set 
free redissolves silica from the Farnham stone ; hence the process is con- 
tinuous. 
MEDICAL SCIENCE. 
Influence of Magnets on Animals. — In the April number of the American 
Psychological Journal there is an extremely 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 particularly directed 
to the subject of this communication in the winter of 1866, when he ob- 
served that a small magnetized steel rod, the ends of which ivere 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 sen- 
sation, 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 sensations, he proceeded to inquire if it were pos- 
sible to recognize 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 
winking ; but the instant the southward pole was applied, no matter with 
how much delicacy, there was a sharp sensation and an involuntary slight 
closing of the eyelid. The effect was faint, but plain. This experiment 
