1851.] OF THE ROYAL INSTITUTION. 37 
In the Library, were exhibited :— 
A Series of Original Views of the Alps by W. Brockedon, Esq. 
Talbotypes taken in Italy by E. Kater, Esq., M.R.I. 
Specimens and drawings of the Caddis-worm, by Mr. T. L. 
Shuckard. 
Centrifugal Pump, by Mr. Appold. 
Fish from the Lias, Barrow-on-Sour [by Mr. Tennant] ; &c. &c. 
A horseshoe magnet, made by M. Logeman of Haarlem accord- 
ing to the instructions of M. Elias, was placed on the table by Mr. 
Faraday. Its weight was 0°98 of a pound and it could carry above 
27 lbs. In the expression of the force of a horseshoe magnet de- 
duced by M. Hecker (p. 28), the power of a magnet of x kilo- 
grammes weight is 10°33 2; in the present case the co-efficient, 
instead of being 10°33, is double that amount. 
WEEKLY EVENING MEETING, 
Friday, March 14. 
Srr Cuarues Fettows, V. P. in the Chair. 
Dr. Gutit, 
On some points in the Physiology of Voluntary Movement. 
Tue Lecturer began with some observations upon the distinctions 
which exist between voluntary movements and the phenomena of 
motion in dead or inorganic masses. In voluntary movement the 
stimulus is within and independent, the elements which are brought 
into play are numerous and complex, and the result is the fulfilment 
of a purpose designed by the individual. 
On the contrary inorganic movements are due to an impulse from 
without : the motion is more general, and does not fulfil any direct 
design. 
In the constitution of animals, besides those which are voluntary, 
there exists the mechanism for a number of subordinate movements, 
which, although they do not present a complete gradation to the 
inorganic forms of motor force, yet follow directly from the physical 
structure of the body, and are altogether independent of the con- 
sciousness and will of the individual. 
The object of the Lecturer was to show the relation of voluntary 
movements to this substratum of natural actions. 
In order to elucidate the subject, attention was first drawn to the 
vertebrate skeleton for swimming, flying, burrowing, leaping, running, 
and walking, and to the purpose which governs these modifications ; 
