670 
POPULAE SCIENCE EEYIEW. 
A Wire Spi'mg Clip has been devised by Dr. Maddox. It is employed by 
him in mounting objects, and will be found of much service to the working 
microscopist. There is no difficulty in making it ; it costs very little, and 
has the advantage of being easily attached to the slide. The inventor gives 
the following directions for the preparation of the clip ; — Take a straight 
piece of brass wire, four and three-quarter inches in length, turn one end at 
six-eighths of an inch with a pair of ty^re-pliers at right angles ; this second 
portion at half-an-inch, again bend at right angles in the same plane ; now, 
at three-quarters of an inch, turn the wire over on itself, having at the bend 
space sufficient to admit a thick slide. At one inch and five-eighths twist the 
wire completely on itself, and bring the now short ends at right angles to the 
longest part ; file this end quite flat. Give the first portion of the ^vire a 
slight curvature, so that the point and bend may act as a stiff spring against 
the under surface of the slide when applied. See the Microscopical Journal^ 
July. 
The Spectro-Microscope. — A most ingenious and useful application of the 
spectroscope to microscopical inquiries has been made by Mr. Huggins. As 
his arrangement differs essentially from that of Mr. Sorby, a short description 
of it will interest our readers. Its greatest advantage is that it can be used 
with the highest objectives (-yVf^h and -Vfh mch). Essentially the plan con- 
sists in arranging the slit of an ordinary spectrum apparatus in the place of 
the eye-piece of the microscope. Behind the object-glass, at a distance of 
three or four inches, an adjustable slit is placed ; the object-glass is focussed 
upon the object on the stage, so that its magnified unage falls precisely upon 
the slit. The opening of the slit, which may be from -^-^th to ^^^yth of an 
inch, allows the light of a small part only of this image to pass on to the 
prisms. If desired, this part of the object may be further reduced by 
shortening the length of the slit. It is obvious that, by the usual stage 
adjustments, any portion of the object can be made to fall within the jaws of 
the slit and to form a separate spectrum. Behind the slit, at its own focal 
distance, is placed an achromatic lens. The pencils emerge parallel, and then 
pass through one or more prisms. The pencils are then received by a small 
achromatic telescope, with which the spectrum is viewed. The eye-piece of 
this telescope is adjusted, so that the lines of Fraunhofer in solar light, or the 
sodium line in an artificial light from a source containing sodium, are well 
defined. The object-glass of the microscope is then to be moved towards or 
from the object on the stage until the longitudinal lines and bars of different 
intensity, due to the darker and lighter parts of the object, are sharply 
defined in the little telescope at the same time as the lines of Fraunhofer or 
the double line of sodium. 
The Quelcett Microscopical Club is the name of a new society instituted for 
the pursuit of histology. It is intended to embrace all those lovers of 
microscopy who, without a claim to be called professional workers, are yet 
deeply interested in the science of histology. The first meeting, at which an 
inaugural address was given by the president. Dr. Lankester, has already 
been held. There is no entrance-fee, and the subscription is very moderate 
(ten shillings per annum). We have every reason to think that the new asso- 
ciation will prosper, and we do not see why — if it is to be composed solely of 
amateurs — it should tend to damage the interests of The Microscopical Society. 
