NOTES AND QUERIES. 217 
Beck’s “CoMPLETE” Microscope Lamp.—The base consists 
of a heavy ring, into which a square brass rod is screwed. The 
square rod carries a socket with an arm, to which the lamp is 
attached. This socket fits the square rod loosely, but is kept in any 
position by a lever which is pressed firmly against the square rod 
by a strong spring. If the lever and the opposite side of the 
socket are taken between the thumb and finger, the pressure of the 
lever on the bar is removed, and the lamp can be raised or lowered 
to the desired position, when by releasing the hold the lamp is at 
once clamped. 
On each side of the burner, and attached to the arm, is an up- 
right rod, to one of which the chimney is fixed, independent of 
the reservoir of the lamp, but fitting closely over the burner, thus 
enabling the observer to revolve the burner and reservoir, and ob- 
tain either a thin intense light or a broad and diffused one, without 
altering the position of the chimney. The chimney is made of thin 
brass, with two openings opposite to each other, into which slide 
3 x 1 glass slips of either white, blue, or opal glass, the latter serv- 
ing as a reflector. 
The reservoir, although holding enough oil to burn for several 
hours, is made very flat, and drops into the annular base, thereby 
bringing the flame of the lamp within 3 inches of the table, render- 
ing it much more serviceable for direct illumination (without the 
mirror) and for other purposes. 
A semicircle swings from the two uprights, to which it is at- 
tached by the pins, placed level with the middle of the flame ; to 
this semicircle is fixed a dovetailed bar, carrying a sliding fitting, 
which bears a Herschel condenser. This condenser, swinging with 
the middle of the flame as a centre, is always at the same distance 
from it; and thus, when once focused, needs no further alteration 
for any change in the inclination of the beam of light. The con- 
denser is fixed at any inclination by a milled head working ina 
slotted piece of brass, fixed to the arm. 
When used for transparent illumination, the condenser is not 
required below the horizontal position ; but when the lamp is re- 
quired for the illumination of opaque objects, the chimney having 
been temporarily removed and the milled head fixing the con- 
denser arm having been loosened, the arm with the condenser can 
be thrown over the lamp, as shown in the illustration, and the 
chimney being replaced, the light, which now comes through the 
opposite opening of the chimney, can be condensed at a large angle 
below the horizontal. 
New Imseppinc MarertaL.—Celloidine is an article made by 
the Schering Chemical works of Berlin. It makes a perfectly 
transparent imbedding medium, a collodion absolutely free from 
