ACCESSORY APPARATUS. 



123 



central ' growing ' cell, which is completed by placing a thin-glass cover 

 over the objects introduced into it, with the interposition of a ring of 

 thin paper, or (if a greater thickness be required) of a ring of cardboard 

 or vulcanite. If the fluid be introduced jp.^ ^ 



into one of the lateral cells, and be drawn- 

 off from the others either by the use, 

 from time to time, of the small glass 

 syringe to be hereafter described (127), 

 or by threads so arranged as to produce 

 a continuous drip into one and from the 

 other a constantly renewed supply is 

 furnished to the central cell, which it 

 enters on one side, and leaves on the x x 



other, by capillary attraction. l Dr. Mad- Maddox's Growing-slide. 



dox's Growing -Slide will be understood from the annexed sketch. The 

 shaded parts are pieces of tinfoil fastened with shellac glue to a glass 

 slide. The minute fungi or spores to be grown are placed on a glass 

 cover large enough to cover the tinfoil, with a droplet of the fluid re- 

 quired. This, after examination to see that no extraneous matter is 

 introduced, is placed over the tinfoil, and the edges fastened with wax 

 softened with oil, leaving free the spaces x x for entrance of air. Grow- 

 ing-slides of this description could be made cheaply with thin glass 

 instead of tinfoil. 2 For an account of a more elaborate apparatus devised 

 by Messrs. Dallinger and Drysdale for the prosecution of their admirable 

 researches hereafter to be noticed (Chap. XL), the reader is referred to 

 the description and figures given by them in the "Monthly Microscopi- 

 cal Journal," Vol. xi., 3874, p. 97. 



122. Aquatic Box. The Live-Box or Animalcule-cage (Fig. 98, A) 

 consists of a short piece of wide brass tube, fixed perpendicular into an 

 aperture of its own diameter in a flat-plate of brass, and closed-in at its 

 top by the object- tablet, a disk of glass with bevelled edges (B); over 

 this box there slides a cover, consisting of another piece of brass tube hav- 

 ing a disk of thin glass fixed into its top. The cover being taken of, a 

 drop of the liquid to be examined, or any thin object which can be 

 most advantageously looked-at in fluid, is placed upon the lower plate; 

 the cover is then slipped over it, and is pressed down until the drop of 

 liquid be spread out, or the object be flattened, to the degree most 

 convenient for observation. If the glass disk which forms the lid be ce- 

 mented or burnished into the brass ring which carries it, a small hole 

 should be left for the escape of air or superfluous fluid; and this may be- 



1 For descriptions of other forms of Growing-Slide, see "Transact, of Microsc. 

 Society,'' Vol. xiv., N.S., p. 34, and " Quart. Journal of Microsc. Science," N.S., 

 Vol. vii.,p. 11. 



2 See his paper on Cultivation of Microscopic Fungi, in " Monthly Microscopi- 

 cal Journ.," Vol. iii. (1870), p. 14. Dr. Maddox recommends the following fluid as 

 sufficiently hygrometric to keep the spores moist, and as adapted to Fungoid 

 growths: 



Dextrine 2 grains. 



Phosphate of Soda and Ammonia 2 " 



Saturated Solution of Acetate Potash 12 drops. 



Grape Sugar 16 grains. 



Freshly distilled water 1 oz. 



The water is to be boiled in a large test-tube or beaker for 15 minutes, and 

 covered whilst boiling and cooling; when settled, it should be poured into per- 

 fectly clean 2-drachm stoppered bottles, and kept for use. 



