1892.] MICROSCOPICAL JOURNAL. 191 



Suppose by these definitions we test the claim of microscopy 

 to be called a science. While the theory of microscopy as con- 

 tained in its journals and in the proceedings of the microscopical 

 societies and in the rich library of works upon the various 

 branches of microscopical technique is a science, the practice of 

 microscopy by the bacteriologist, the zoologist, the chemist, the 

 entomologist, the mineralogist, the pharmacist, etc., is an art. 

 There is a science of microscopy , and in its practical applications as 

 an art it has given birth to an ever widening circle of sister arts, 

 each of which is the ready handmaid of some particular branch 

 of knowledge. 



If any one sliould ask whether or not there exists any collection 

 of the general principles or leading truths relating to the manipu- 

 lation of microscopical apparatus, the many treatises and pub- 

 lications at our call will be a full and sufficient answer. Take, 

 for example, such a finished work as Dr. James' " Technical Ilis- 

 tor}' of a Slide," and who would assert that this masterly little 

 treatise is not a collection of general principles and leading truths, 

 arranged in an orderly and scientific manner, and that it does not 

 render our knowledge of how properly to mount a slide " cer- 

 tain," or deny that by its aid the mind acquires full comprehension 

 and understanding of the truths and facts which pertain to micro- 

 scopical technique ? 



The special knowledge concerning the use of any tool or ma- 

 chine, if of sufficient importance to be generalized, when properly 

 generalized becomes a science, while the application of these 

 scientific principles in the practical use of the machine or tool lie- 

 comes an art. Manifestly the more complex the mechanism, and 

 the more wide-spread its practical applications, the more justifi- 

 cation for generalizing the special knowledge peculiar to the ma- 

 chine, and elevating it to a science. Microscopy arrived at that 

 point long ago. 



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

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

 single hair which was 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 having committed 

 the assault. 



