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THE MICROSCOPE. 45 
solution of acetic acid for a few hours. Wash again in clean water, 
and transfer to slip, and drop on spirits of wine; arrange the object 
and put over another clean slip; gently press and lightly fasten with 
thread; place end down in a small quantity of spirits of wine for a 
few hours. Then remove the thread and gently lift off one slip, the 
whole still wet with the spirit, when the object will adhere to one of 
the slips; drop on absolute alcohol and work object into centre of 
slide. Then apply oil of cloves, and in a few hours the object will 
be ready for the balsam to finish. Royal Mic. Jour. 
Dr. Hermann Fol, in studying the Infusoria, found great diffi- 
culty in killing these minute objects in an extended condition. 
Osmic, acetic, chromic, and picrosulphuric acids were tried in vain; 
finally he succeeded with perchloride of iron. After treatment with 
this new reagent, the objects are washed with alcohol, and stained 
with gallic acid, which produces a brownish coloration and renders 
the nuclei very distinct. The specimens thus treated are mounted 
in balsam, or, better for observation, in glycerine. 
SaD FaTE OF THE YELLOW FEVER Micrope.—M. Lacerda, 
of Lisbon, found in the liver and kidneys of yellow fever subjects a 
parasite, supposed to be the infective principle. Portions of these 
organs containing the parasite were examined by MM. Cornil and 
Bebes, but these expert sceptics ascertained that Lacerda’s microbe 
consists of bits of vegetable tissue and pigment.—Zxeunt omnes.— 
Phil. Med. News. 
RECONSTRUCTION OF OBJECTS FROM MICROSCOPIC SECTIONS.— 
Born gives an elaborate description of his method of modelling, 
which is really very simple as well as ingenious. The sections are 
made with great care, all of the same thickness: they are next drawn 
with the camera, and the outlines transferred to wax plates, the 
thickness of which is chosen so as to correspond in relation to the 
thickness of the sections, as do the outlines to the superficial dimen- 
sions of the sections; or, in other words, each wax plate is cut out 
so as to represent the actual section equally magnified in all three 
dimensions.— Science. 
