176 THE MICROSCOPE. [August, 



objects, and his preparations of type specimens of the diatoms ot 

 Bel^iimi, on which his ^'synopsis" was founded, rendered him 

 by far the most important exhibitor at the exposition. The fourth 

 edition of liis book on the microscope was brought out on this 

 occasion, and it was so freely rewritten from the former edi- 

 tions as to be essentially a new book. The modern optics and 

 present construction of the microscope are adequately discussed, 

 the latter, naturally, most fully from continental experience. The 

 general management of the microscope and preparation of objects 

 is included, photomicrography and the staining and slicing of 

 tissues having prominence according to the fashion of the time ; 

 but the application of the microscope to the stud}' of plants, and 

 especially of diatoms, is omitted, to appear as a special volume 

 hereafter. Desiring to make the j^resent volume worthy and able 

 to serve as a '•^ livre de luxe'" commemorative of the occasion 

 without the natural impediment of a proportionally high cost, the 

 accomplished author secured its publication in a grand volume at 

 his own expense, and had it sold at a price that could scarcely be 

 believed to cover the cost of printing. Even to those fortunate 

 enough to have received the beautiful '' diploma of honor," this 

 souvenir volume by Dr. Van Heurck will be second to nothing 

 as a keepsake of the Antwerp Exposition. 



DETECTION OF CRIME. 



The Microscope and a Hair. — Two different men were sus- 

 pected of making an assault but no proofs were forthcoming. A 

 single hair which w^as found on the clothes of the victim finally 

 became the clue to the mystery. 



The hair was photomicrographed and compared with photo- 

 micrographs of the beard and hair of each suspect. There was 

 entire lack of similarity and the case was about to be abandoned. 

 The hair was pointed and had never been cut. Other facts 

 pointed to its belonging to a smooth-haired and comparatively 

 short-haired dog. Inquiry revealed the fact that one of the suspects 

 owned such a dog. A fresh hair agreed in every respect with 

 the specimen. The owner of the dog could not explain away the 

 facts and was convicted. He also confessed to have committed 

 the assault. 



o 



# 



Marshall's Zoophyte Trough. — This life-cell is made by 

 fixing any sized circular cell to a slip, and cementing over one- 

 half of this cell a semicircular piece of thin glass. It can then be 

 used as an ordinary trough when inclined, or as an open cell 

 when lying flat. 



