Microscopy at the American Hexhibition. By R. H. Ward. 27 
attractive appearance. ‘The large number of standard forms and the 
numerous and convenient accessories made by this firm have been 
so extensively exhibited and sold in-this country that their’ pecu- 
liarities are well known. ‘The chief novelties are a much-needed 
addition of centring and rotating adjustments to the sub-stage, and 
a showy introduction of aluminium mountings in some of the 
stands. 
Henry Crouch, of London, also exhibits a full series of instru- 
ments characterized by a greatly improved quality of moderate- 
priced work, a class of work for which there is an increasing 
appreciation and a growing demand. His best stands of medium 
size lack scarcely any advantage as compared with far more clumsy 
and costly first-class stands. His variety of acsessories is large 
and well selected, showing an earnest endeavour to adopt the best 
novelties from every source. His manufacture of a small histological 
instrument, with short body, low stage, and horge-shoe base, after 
the Continental method, is one more evidence of the growing 
favour with which such instruments are regarded in England and 
America, especially as it is sold at a price greatly disproportionate 
to its size and elegance. 
Of Negretti and Zambra it need only be said that along with 
other goods they display a small variety of microscopes, of which 
but one, the largest, 1s notable, and that merely for its bigness. It 
belongs to the furniture style of instruments, and so does its large 
case of accessories. Precisely the same words may be applied, 
except as to numbers, to the two huge instruments of J. H. Dall- 
meyer, the smaller of which is, in the writer’s judgment, too large 
for any known use. 
The class of American instruments, though not as distinct a 
group as the other two, is mentioned separately for local reasons as 
well as on account of some peculiarities which its members have in 
common. Certainly first among these is the exhibit of Joseph 
Zentmayer, of Philadelphia, who offers the most elaborate and 
elegant instruments as well as the largest variety of different 
forms. His ingenious contrivances and excellent brasswork are 
too familiar to need description. He shows the large American, 
intermediate, hospital, and clinical stands, and the new student’s, 
introduced a few years ago to meet the demand for histological 
instruments ; also a material modification of the American, intro- 
duced this summer and known as the model, having the three new 
features of a fine adjustment by a long slide close behind the rack 
and moved by a screw and lever nearly in the Ross position, an 
interchangeable stage which can be almost instantly removed and 
replaced by an extremely thin diatom stage, and a bar, which 
carries the sub-stage and mirror, hinged at the level of the plane of 
the stage so as to enable the illuminating apparatus to revolve with 
