Miscellaneous. 159 
in pyriform sacs, appended on all sides to a comparatively small 
central part, from which the trunks of the nerves originate. The 
cerebrum and the other ganglia, like those of the great sympathetic 
nerve, present the appearance of small racemes; and if we wish to 
ascertain the origin of the nerves, it is in the midst of these masses 
of granules that we must seek it, notwithstanding the difficulty which 
this presents.—Comptes Rendus, Nov. 20, 1865, p. 906. 
On a new Kind of Illumination for Opaque Objects under High 
Powers. By Messrs. Smiru, Becx, and Beck. 
This method of illumination has been recently introduced by Mr. 
Smith, of Kenyon College, U.S.*; the best effect may, however, 
be obtained by the following exceedingly simple plan :-— 
Fig. 2. 
A piece of thin glass (4), attached to a small brass milled head 
(fig. 3), fits into the side of an adapter (fig. 1); and when in po- 
sition, as in figs. 1 and 2, the light coming through a small circular 
aperture (a) may be reflected down and through the object-glass by 
the thin glass, which makes no obstruction to the rays of light passing 
upwards again from the object-glass to the eye-piece, nor even affects 
the definition to any perceptible degree. 
The adapter (fig. 1) is used, as shown in section (fig. 2), between 
the nose-piece (c) and the object-glass (d); it has a rotating fitting 
at the milled ring; and this movement, in combination with that of 
the small milled head to which the thin glass is attached, is sufficient 
for the nicest adjustment of the illumination. By means of a slot 
(e, fig. 1) in the side of the adapter, the thin glass may be readily 
removed for the purpose of being wiped, as its perfect freedom from 
dust or smear is most essential. 
* Silliman’s Journal, September 1865. 
