ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
823 
has had so much to do with the formation of the magnificent collection 
of Mr. Crisp. Permit me to remind you, that as citizens and sovereigns 
of the Republic, the Medical Museum belongs to you, and that as 
American microscopists its collection of Microscopes and of microscopic 
slides and material should be a matter for your special interest and care. 
The collection is very far from being complete, it is only the beginning 
of what I hope will one day be gathered and carefully preserved in it, 
namely a specimen of every different form of Microscope, and especially 
of the earlier forms of American makers, of which we have none, and 
also specimens of the best work of American microscopists which can 
be shown by permanent preparations, and to secure this I ask your 
assistance. 
The library of the Surgeon-General’s office, connected with the 
Museum, is rich in books and journals relating to the Microscope and its 
uses, especially in its applications to biology and the medical sciences, 
and it is available to all who wish to use it. If you are not familiar 
with its resources and its index, I hope you will become so while you 
are here.” 
Recreative Microscopy.* — Mr. Henry Ebbage communicates the 
following note : — “ A pretty object for entertaining friends is the arbo- 
rescent growth of silver crystals. To show this, dissolve a small crystal 
of silver nitrate (or a piece of lunar caustic) in a few drops of rain- 
water. Place a drop of this solution in the centre of a slip of glass, 
and arrange it under a low power of the Microscope, concentrating the 
light from above by means of a stand condensing lens. Now take a 
piece of copper bell-wire 1J in. long, and bend it like a capital L, then 
bend the longer limb to form a hook, which will rest anchor-fashion 
when laid down. Place this at the side of the drop of solution, allowing 
the hook to dip into it at the edge. Chemical exchange results, copper 
going into solution, and silver crystallizing out. 
N.B. — Do not spill the solution as it stains black.” 
Technique.! 
Cl) Collecting 1 Objects, including Culture Processes. 
Methods of Bacteriological Research.^ — In an article of twelve 
pages Dr. Kirchner gives a compressed but clear account of all the 
methods of bacteriological research, and this is prefaced by a review of 
the general morphological and biological characteristics of bacteria. 
The most important of the microscopical and cultivation methods 
are described with an accuracy of detail so that they are available for 
practical work. 
At the end of the article are considered the examination of water, 
air, and soil, and also that of infectious diseases. 
* English Mechanic, liv. (1891) p. 19. 
t This subdivision contains (1) Collecting Objects, including Culture Pro- 
cesses ; (2) Preparing Objects ; (3) Cutting, including Imbedding and Microtomes ; 
(4) Staining and Injecting; (5) Mounting, including slides, preservative fluids, &c.; 
(6) Miscellaneous. 
X ‘ Handworterbuch der Gesundheitspflege,’ pp. 69-80. See Centralbl. f. 
Bakteriol. u. Parasitenk., x. (1891) p. 234. 
