Journal of Applied Microscopy. 



13 



Journal of 

 Applied Microscopy. 



Issued Monthly from the Publication Department 



of the Bausch & Lomb Optical Co., 



Rochester, N. Y. 



L. B. ELLIOTT, Editor. 



Address all communications to 

 Publication Department, 



BAUSCH & LOMB OPTICAL CO., 



Rochester, N. Y. 



Entered at the Post-office, Rochester, N. T., as second-class matter. 



JANUARY, 1898. 



EDITORIAL. 



Raison d'Etre. 



Specialization is the order of the day, 

 and the specialist has time for his par- 

 ticular specialty only. It is thus neces- 

 sary for every branch of science, art or 

 industry to have its own particular me- 

 dium for the collection and speedy dis- 

 semination of information essential to 

 its development. It seems almost unac- 

 countable that in America, where the 

 microscope and apparatus accessory to 

 it is so extensively used in educational 

 and industrial insititutions, there should 

 be no periodical devoted to microscopical 

 instruments and technique viewed from 

 a practical standpoint. Such is never- 

 theless the case, and such writings as 

 are g-iven to the public are either scat- 

 tered throug-h a variety of publications 

 properly dealing with other subjects, re- 

 ports, bulletins or the microscopical jour- 

 nals of foreign countries, of which there 

 is an abundance, liberally and well sup- 

 ported. Believing therefore that there 

 exists a demand for such a publication, 

 the Journal of Applied Microscopy is 

 presented to the users of microscopes, 

 with the statement from the publishers 

 that it will be conducted on an entirely 

 independent basis, beginning in a very 

 modest Way, but with the promise that 

 it will be expanded in direct proportion 

 to the support received from those en- 

 gaged in practical microscopical work. 

 In other words, it is intended that the 

 Journal shall be just what its con- 

 tributors and supporters make it. It will 

 be a progressive record of new apparatus 

 of every kind bearing on the operations 

 leading up to and including the use of 

 the 'microscope, improvements in 

 apparatus and new applications of 



apparatus already existing, methods 

 of working, new and useful formulae, 

 discussion of matters relating to 

 the above subjects, digests of simi- 

 lar matter appearing in foreign 

 journals, and news and notes about 

 institutions and men here and abroad. 

 We realize that the success of the 

 Journal depends upon the support of 

 those interested in the advancement of 

 the practical side of science, and trust 

 that all will take advantage of the op- 

 portunity here presented to build up a 

 representative American publication for 

 applied microscopy. 



Magnifying power, in the minds of 

 many persons, seems to be the aim and 

 end of the microscope. This opinion pre- 

 vails with many possessors of micro- 

 scopes, although it is most common with 

 the laity. A hig-hly sensational and lu- 

 dicrous article on a new method to obtain 

 this result appeared in a New York news- 

 paper some time ago and went the rounds 

 of the press of the country. The mis- 

 chief done by one such article can never 

 be entirely obliterated, but in order to 

 counteract its influence as much as pos- 

 sible we shall recur to the subject in a 

 later issue. 



Magnifying power, as a quality in it- 

 self, is valuable only so far as it dis- 

 closes what we wish to see. Any increase 

 of power beyond this, is of no value what- 

 ever. Microscopic vision depends upon 

 the resolving power, and this in turn 

 upon the angular aperture, of the objec- 

 tive. Resolving power alone is of no 

 value. The image created by the objec- 

 tive must be magnified to such an extent 

 as to make the detail we are looking 

 for visible to the eye, and an increase in 

 power simply separates the detail; if this 

 proceeds too far it reduces the definition 

 and light. 



"When we say that resolving power de- 

 pends upon angular aperture, it is of 

 course assumed that the objective is a 

 typical one, that the chromatic and 

 spherical aberrations are properly cor- 

 rected, and that it is properly construct- 

 ed mechanically. 



We know what each additional degree 

 of angular aperture will give in resolving 

 power, as well as the limit of visibility 

 with the greatest angular aperture, and 

 there is no hope of obtaining more detail 

 by the mere increase of power. 



* * * 

 A cordial invitation is extended to 

 those who have worked out practical 

 methods, to give their fellow workers 

 the benefit of their researches in the 

 Journal. A simple, cer'tain method of ar- 

 riving at a definite result is always of 

 service. The description of the method 



