The Microscope. 15 



is this, the italics being his : " The Continental Model. — Our 

 one purpose in this treatise is to endeavor to promote what we 

 believe to be the highest interests of the microscope as a 

 mechanical and optical instrument, as well as to further its ap- 

 plication to the ever-widening area ©f physical investigation to 

 which, in research, it may be directed. To this end throughout 

 the volume, and especially on the subject of the value and 

 efficiency of apparatus and instruments, we have not hesitated 

 to state definitely our judgment, and, where needed, the basis 

 on which it rests. Incidentally we have expressed, perhaps 

 more than once, our disapproval, and with ourselves that of 

 many of the leading English and American microscopists, of the 

 form of microscope known as the Continental model; and we 

 cherish strong hopes in the interests of the science of micro- 

 scop}'' that so enterprising and eminent a firm as that of Zeiss, 

 of Jena, will bring out a model that will comport more com- 

 pletely with the needs of modern microscopical research than 

 even the best of the models that the}^ now produce. * * * 

 And when we know that the ' Continental model ' has in the 

 hands of Zeiss passed from an instrument without inclination 

 of the body into an instrument that does so incline, and from 

 an instrument without sub-stage or condenser into one provided 

 with the latter of these absolutely indispensable appendages, 

 and finally from an instrument with a perfeetl}^ plain stage 

 with ' clips ' into what is now a stage with mechanical move- 

 ments — we can but hope that these concessions to what 

 has belonged to the best English models for over forty years, 

 may lead to an entire reconstruction of the stand — a wholly 

 new model — intended to meet all the requirements of modern 

 high class work in all departments, and with a fine adjustment 

 of the most refined class." This should be enough to show that 

 the Continentalists can not be an increasing factor in the ad- 

 vanced microscopy of the present day, but Dr. Dallinger gives 

 them six octavo pages more of the same commendable opinion. 

 That the sub-stage condenser should be used in all classes of 

 work is strenuously insisted upon, and that it should be used 

 with its full and largest aperture and accurately focused, so 

 that the posterior lens of the objective, as the microscopist 

 looks down the body after removing the eyepiece, should be seen 

 te be three-fourths full of light. That this is correct teaching 



