MICROSCOPY. 779 
i his readers. But if the draughtsman publishes his figure as ex- 
= plicitly as his theory, not as the representation of the ‘severe 
fact,” then he will be understood. 
On the other hand, the camera represents exactly what may 
be seen by any other observer, using the same appliances (which 
should in all cases be described) and the student can draw his own 
conclusions from the picture as to the soundness of the theories 
advocated. But then it must be remembered that a photograph 
can represent only one view of an object, while the observer by 
changing the focus of his instrument obtains a new view at each 
movement of the screw. With the high power lenses now in use, 
these differing views are all important for correctly understanding 
almost any object. Therefore scarcely anything can be properly 
illustrated by one photograph. Many objects must require several. 
TES 
This inflexible limitation of the photographic view to one sec- 
tion or plane of the object, is evidently one of the points re- 
ferred to in the criticism quoted above, which, without referring 
to photography as a means of proof of alleged observations, or of 
submitting observations to investigators for criticism or deduction, 
only suggested that for communicating well ascertained facts a. 
Skilful delineation may contain more information than any avail- 
able number of photographic representations. A good drawing, 
as intimated by Dr. Beale, may often supply the place of a long 
_ and unread verbal description. 
Tue Susmersion Mrcroscore. — Mr. Richards has presented 
to the Royal Microscopical Society an adjustable submersion tube 
Which can be attached to any objective, thus avoiding the neces- 
% sity of having a tube specially fitted to each objective which is to 
be used in this manner. | : 
Dr. Dudgeon’s paper in the ‘ Quarterly Journal of Microscopi- 
Cal Science ” for July, 1871, seems to claim originality for the idea 
a of a submersion arrangement, but Mr. Richards and others have 
Called it Mr. Stephenson’s plan. We hope our London contempo- 
taries will settle this question of priority, and give us o facts 
immediately. All the submersion arrangements are but slight va- 
tations of a single idea, and that for the present we credit to Dr. 
Dudgeon. : 
Tur Micro-pantocrapa.— Mr. Isaac Roberts publishes in the 
2 July | number of the ‘* Monthly Microscopical Journal” an illus- 
