Notes. 
438 
[July, 
perfection must be sought for in a lens whose focus = 15 times 
its aperture. What shall we say, then, of the binocular field- 
glass the focus of whose objectives does not exceed 3 times their 
apertures.” “ It is a sad faCt that at the present day the terres- 
trial telescope, apart from the navy, is only to be found in the 
hands of scorers for rifle-shooting, and of a few infatuated indi- 
viduals who still persist in carrying about these antiquated in- 
struments.” Mr. Nelson gives a good account of the most useful 
kinds of telescopes made ; also their respective uses, and what 
kind of performance may reasonably be expeCted from them. 
Very full directions are given for the testing of terrestrial tele- 
scopes, and the reader is put on his guard against two very 
common defeCts,— error in the size and position of the diaphragm 
in the ereCtor, and the cutting off of the aperture of the objeCt- 
glass by the insertion of stops. Only those who have made use 
of a good small telescope know what can be done with it. It is 
one of the field naturalist’s most valuable tools : an animal can 
be watched, the face of a cliff examined, plants detected, geolo- 
gical details noted, and, if the focussing slide is long enough, 
an observation can be taken at as short a distance as 20 feet ; 
the view given is surprising, the details of flowers and inseCts 
are rendered in a manner almost microscopical, and the picture 
rendered brilliant by its isolation from all surroundings ; and the 
instrument doing all this will give a splendid view of the moon, 
and show Jupiter’s satellites and Saturn’s ring. 
J. Schlesinger (“ Ze'itschrift des (Ester. Ingenieur-Vereins ”) 
maintains that the doCtrine of the inertia of mass is an error, and 
attempts to explain all mechanical and other physical phenomena 
by assuming that space is an absolutely persistent and fixed 
substance penetrable by all the real things of the world, and 
that energy is also a substance penetrable by all the real things 
and moving in a capillary manner in the fixed substance of 
space. [The term “ real ” is here taken in its philosophical 
sense.] 
The total number of licenses for physiological experimentation 
during 1884 was 49, and the number of experiments performed 
was 145. Of these 99 consisted simply in the introduction of a 
virus ; 24 were experiments in cases of suspected poisoning ; 
10 were experiments on the aCtion of certain Fungi upon fish, 
and 5 on the effeCts of absolutely pure water upon fish. [So 
much for the “ cutting up alive.”] 
The French Association for the Advancement of Science will 
meet at Grenoble, August 13th, 1885, under the presidency of 
Prof. Verneuil. 
M. Richard (“ Comptes Rendus ”) has examined the effeCt of 
cocaine upon the pulmonic gasteropods, earthworms, crustaceans, 
hydrse, &c. 
