MICROSCOPY. 879 
is perhaps as annoying as if the plate, instead of its image, were 
in the focus of the eye lens. 
Tur Micro-sprcrroscorr. — Dr. E. J. Gayer has contrived and 
published in the Transactions of the Royal Microscopical Society, 
a micro-spectroscope consisting of a collimating lens and one or 
more prisms occupying the position of the ocular, and immedi- 
ately above these a telescope, suitably inclined, for examining the 
spectra. According to Hogg, and other authorities, the first appli- 
cation of the spectroscope to the microscope was made by Mr. H. 
C. Sorby who placed a triangular prism below the stage, the object 
being situated in the spectrum. As this was inapplicable to 
opaque objects, Mr. Huggins proposed to adapt a direct vision 
spectroscope to the ocular, which he accomplished by inserting the 
collimative-tube of a star spectroscope into the body of the micro- 
Scope in the usual position of the eye-piece. The Sorby-Browning 
contrivance has so completely superseded these arrangements that 
they have been nearly forgotton, and Dr. Gayer has rediscovered 
Mr. Huggins’ arrangement without knowing it. He combines with 
it the Sorby-Browning plan of adding a side stage for the com- 
parison of spectra, and seems to secure an increase of light by 
Placing the slit nearer the objective, about an inch above it. On 
the other hand, those most familiar with the Sorby-Browning eye- 
Piece form, claim that it has sufficient light and dispersion for its 
use, and that its absorption bands are not only wide enough but 
more distinct than if magnified by a telescope. 
Bricurs on Tea anp Corrox. — Mr. M. C. Cooke describes a 
new species of fungus occurring on blighted leaves of the tea plant, 
from Cachar, India. “Hendersonia theecola Cooke, Perithecia glo- 
bose, black, prominent, pierced at the apex, scattered over both 
surfaces, or subgregarious ; spores cylindrical, rounded at the ends, 
triseptate, pale brown, on long hyaline pedicels (.0004—.0005 in.), 
-01-.0125 millimetres long without the pedicels: on leaves of 
Thea,” Picking off the diseased leaves and burning them is the 
only remedy suggested for this blight, which shares with the punct- 
ures of an unknown insect the credit of destroying the plants. 
Seeds of American cotton naturalized at Dharwar, India, af- 
fected with « Black blight,” manifested but little injury externally, 
but on being crushed were found to be filled with a sooty powder 
aPpearing like the spores of an Ustilago. On closer examination 
