THE AMERICAN 



MONTHLY 



MICROSCOPICAL JOURNAL 



Vol. V. 



"Washington, D. C, August, 1884. 



No. 8. 



Growing Slides or Microscopical 

 Vivaria. 



A good growing slide, in which 

 minute organisms may be kept alive 

 for days or weeks, is of great value 

 to a microscopist. It is useful not 

 only for purposes of study, but also 

 for exhibiting objects to friends or at 

 public gatherings. It is very trouble- 

 some to prepare minute and delicate 

 living objects for exhibition, when 

 they have to be sought for in a bottle 

 of water that has been carried about 

 from home to the place of meeting. 

 The chances are that they will not be 

 found at all, and if they are found 

 they are not likely to be shown to 

 good advantage, owing to the haste 

 in preparation. 



It is far better to put the specimens 

 in a live-box or zoophyte trough at 

 home, and the latter may be carried 

 about upright in a large bottle of 

 water. 



The importance of this subject in- 

 duces us to repeat, with some addi- 

 tional details, the descriptions of two 

 forms of growing slides, which have 

 already been given in these columns. 

 The first is the growing slide devised 

 by Mr. T. Charters White, which he 

 described before the Quekett Club 

 about three years ago. 



' The sides, which may be of any 

 dimensions for which you can get 

 thin glass covers, are constructed out 

 of the strips of thick plate-glass. 

 Having built up a cell with these, to 

 a suitable and convenient size, cement 

 a piece of the same plate-glass in the 

 centre of the cell with Canada bal- 

 sam. You have now a water-tight 

 cell with a table of plate-glass in tJie 

 centre, the space round which you 



may fill half up with water. Plac- 

 ing the infusoria, or whatever the ob- 

 ject may be, on this table in water, 

 cover it with the thin glass, and the 

 water in the trough will keep up the 

 loss by evaporation.' 

 ' Such a slide must be used with the 

 microscope vertical, which is a de- 

 cided objection. A more generally 

 useful growing slide, or vivarium as 

 he prefers to name it, was described 

 by Mr. J. D. Hardy before the same 



Fig. 24. — Hardy's Vivarium. 



club at about the same time. We 

 reproduce the drawing in fig. 24. It 

 consists of two plates of glass, three 

 inches long by two wide, with a ring 

 of glass or other material, having 

 part cut away as shown in the cut, 

 between them. The plates are held 

 are held together by rubber bands, 

 and the joints are made tight by 

 grease or other material. The au- 

 thor says : — 



' To use it, take oft' the upper glass, 

 and having cleaned both glasses, place 

 the object on the lower glass, manip- 

 ulate it to the best advantage, replace 

 the upper glass, and then fill up with 

 water through the hole at the top. It 

 will be found that the cell is reversi- 

 ble and that it can be plunged into a 

 beaker full of water in any position 

 without any fear of losing the object.' 



