632 
Notes. 
Mr. J. W. Stephenson considers the swinging sub-stage of 
comparatively little value, as it is unable to utilise the full aper- 
ture of the modern homogeneous immersion objectives : this can 
only be done by means of immersion illuminators, which are used 
on the ordinary rigid sub-stage arrangement. 
Dr. H. R. Rogers (“ Progress of Science ”) considers the sun 
not “ the manufacturing place and distributing reservoir of aCtual 
light and heat,” but “the source whence the whole solar system 
is supplied with the invisible potential light and heat which be- 
come developed where required.” The great central orb may 
therefore be regarded as like unto the earth on its surface and in 
its surroundings, viz., a dark, cold, habitable body. 
The newly-invented instrument, by means of which the exaCt 
position of the bullet in the body of the late President Garfield 
was supposed to be traced, must of course fall into discredit now 
the autopsy has shown that its indications were erroneous. 
It is reported that M. Pasteur is about to visit the Bordeaux 
lazaretto, in order to make a special study of yellow fever, and 
determine whether it is due to a parasite, and if it can be pre- 
vented by a kind of inoculation. 
“ II Progresso” considers that sulphuric acid is slightly volatile 
at ordinary temperatures. 
Dr. Alcott, of the “ Concord School of Philosophy,” pro- 
nounces matter “ a precipitate of thought ”- — whatever that may 
mean. 
According to “ L'Union Medicale ” the ancients employed 
eledfricity as a therapeutic agent, making use of a living torpedo 
(Raid torpedo) as a source of the agency. 
A Sanitary Congress has been opened in Vienna. 
Signor O. Comes (“ Atti della R. Accademia dei Lincei ”) has 
published the results of his investigations concerning the influ- 
ence of light upon the transpiration of plants. He finds that the 
emission of watery vapour from a plant depends not merely on 
the agencies which influence the evaporation of water from an 
open surface, but also on the adtion of light, and consequently 
reaches a daily maximum shortly after noon. In case of a 
coloured organ only those rays of light are effedtive which are 
absorbed, and not those which are refledted. 
