SCIENTIFIC SUMMARY. 
477 
MICROSCOPY. 
New Class and Demonstrating Microscope. — In teaching histology to large 
classes of students, two forms of microscopes are required : one for the 
laboratory, with which the student himself works, 
and one for the class-room, which the lecturer 
hands to the nearest student, who passes it to his 
neighbour, and so on till it travels round the class. 
The idea of combining these two forms in a single 
microscope occurred to us as being both economical 
and convenient. The instrument represented in the 
adjoining cut was therefore prepared for us by 
Mr. Collins, of Titchfield Street. Pig. 1 represents 
the microscope as used in the laboratory, with a 
double nose-piece bearing a 1 -inch and i-inch object- 
glass. Fig. 2 shows the microscope as used in the 
Pig. 1. As used in the Pig. 2. As used in the Lecture-room. 
Laboratory. 
NEW CLASS AND DEMONSTRATING MICROSCOPE. 
lecture-room : the leg is drawn out from the sliding tube, which works in 
the knuckle joint in the solid metal foot, and bears the mirror; on this 
there is fitted a small oil-lamp, and the instrument being grasped by the 
curved portion between the body and stage, and used like a telescope, trans- 
parent objects placed on the stage are seen with the greatest distinctness. 
It is remarkable, but it is no less true, that no amount of ordinary flickering 
of the flame is perceptible by the observer. The instrument is provided 
with a good 1 -inch and also 5 -inch objective, which show the markings on 
Pleurosigma formosum most satisfactorily. The instrument is intended to 
meet the want of teachers in medical schools 
and public institutions, and has just been 
selected for the histological laboratory at 
St. Mary’s Hospital. 
An Adjustable Notating Microscope-table 
has been devised by Messrs. Loam and 
Fearns, and is likely to be useful to those 
who use a circular table when exhibiting NEW rotating microscope table. 
microscopic objects to a number of persons. 
It is triangular in form and, when placed in position, its apex corresponds to 
