1883.] 



MICROSCOPICAL JOURNAL. 



149 



Passing along to where the culture 

 of oysters is illustrated and explained, 

 we observed, in several places, micro- 

 scopes arranged to show the young 

 oysters or "spat " as it is called, and, 

 as it has been a matter never fully ex- 

 plained to us how the young oysters 

 for mounting were obtained, we took 

 occasion to inquire of one gentleman 

 who had some " spat " in a bottle es- 

 timated to contain 1,740,000 young, 

 all from a single oyster. These were 

 obtained bv placing the oyster in a 

 vessel of salt water until the spat was 

 discharged naturally, after which it 

 was collected and bottled. There is 

 much more in the exhibition worthy 

 of notice, but we must defer more ex- 

 tended remarks until a future time. 



Mounts and Mounting. 



[The following article is an abstract 

 of two papers read before the Man- 

 chester Science Association and the 

 Manchester Microscopical Societv, by 

 Mr. E. Ward, F. R. M. S. Mr. Ward 

 has had great experience in mounting, 

 and he does a large trade in micro- 

 scopical slides of his own preparing. 

 The articles are published by him in 

 a small pamphlet, and entitled respec- 

 tively, " Microscopical Mounts and 

 Mounting" and "Micro-crystalliza- 

 tion. — Ed.] 



In the early days of the microscope, 

 mounting must have been a very differ- 

 ent matter from what it is now, and 

 as I use (and sometimes break) circle 

 after circle of covering glass, I like to 

 think that it was before my time that 

 mica or talc was used for the same 

 purpose. 



I believe that one of the earliest 

 methods of so-called " permanent 

 mounting" was by placing the ob- 

 jects (thin enough to be examined by 

 transmitted light, without preparation) 

 between two thicknesses of mica, and 

 putting these between two card- board 

 slips having a hole punched through 

 them. A little later, so far as I can 

 learn, the plan was adopted of placing 



the two mica flakes, enclosing objects 

 prepared in the same simple manner, 

 in slips of wood, bone, or ivory, each 

 of these slips sometimes containing 

 several objects. 



I wish that I could follow, chrono- 

 logically, the many improvements 

 made in microscopical mounts — one 

 of the greatest was the introduction 

 of Canada Balsam. 



It had long been felt to be one of 

 the greatest needs in the preparation 

 of objects, that some medium should 

 be discovered in which the more 

 opaque ones could be well displayed. 

 That such a medium had been found 

 was shown at a meeting of Micro- 

 maniacs, held at the residence of one 

 of their members, where, on an even- 

 ing, some forty years ago, some ob- 

 jects were placed under the micro- 

 scope, which, from the clearness and 

 distinctness o^Le view, caused great 

 delight to thl^^olders, who naturally 

 wanted to learn how these (to them) 

 most magnificent results were obtained. 



The disappointment must have been 

 intense when they were told that this 

 was a profound secret, known only to 

 three persons, each one of whom was 

 pledged to the others not to divulge 

 it ; but a gentleman present, while 

 holding up one of the slides for ex- 

 amination, pressed the glasses to- 

 gether between his fingers, and when 

 warned of the danger of thus handling 

 newly-mounted specimens, changed its 

 position and held it by its opposite 

 edges. But he had already pressed 

 out a very small portion of the mount- 

 ing medium, which, smearing his 

 fingers, disclosed, by its now well- 

 known scent, the secret of mounting 

 in Canada Balsam, and we enthusiasts 

 may imagine the delight of this worthy 

 worker, when, without any underhand 

 action, he had thus "smelt " his way 

 to results similar to those so much ad- 

 mired. But we, most of us, have, 

 early in our work, learned that there is 

 a difference, and a vast one, between 

 l^owing that an object is mounted in 

 Canada Balsam and being ourselves 

 able to mount in this medium ; and 



