PRACTICAL BOTANY 



*16. Drawing-paper or card, with a hard smooth surface, or 

 a note-book of such paper, without lines. 



*17. Hard pencils (H. or H.H.H.) and india-rubber. 

 *18. Gummed labels (1 in. x f in.) for naming slides. 

 *19. A coarse duster, and a finer cloth, e.g. an old pocket- 

 handkerchief. 



20. A rack for keeping slides temporarily, and a bell-glass 

 to cover it. 

 *2l. A simple lens. 



*22. A compound microscope. This should be one of the 

 smaller stands with a short tube, e.g. Hartnack No. III. A, or 

 Zeiss No. V., VI., or VII. : similar stands of varying merit 

 are to be obtained from most of the English makers. The 

 microscope should be provided with 



*i. High and low eye-pieces : the longer is the lower 



power, the shorter the higher. 



*ii. Two objectives, the lower power (Zeiss A, or Hart- 

 nack No. 3) of about 1 inch focal length. The 

 higher (Zeiss D, or Hartnack No. 7) about one-sixth 

 inch or one-eighth inch focal length. 

 *iii. A micrometer, either adapted to the eye-piece, or a 



stage micrometer. 



iv. A nose-piece to carry two, or, if necessary, more objec- 

 tives : its use will save much time, 

 v. A camera lucida for drawing, 

 vi. An erecting eye-piece is also a useful adjunct, when 



dissection is to be carried on under the microscope. 

 *23. A rack or tray to hold small glass-stoppered bottles con- 

 taining reagents : the following are the reagents which are in 

 most constant use 



*a. Weak glycerine, i.e. Price's pure glycerine diluted 



with an equal volume of distilled water. 

 *b. Caustic potash: make a 2 per cent, solution of the 

 solid sticks of caustic potash in distilled water, and 

 filter. 

 *c. Acetic acid : one volume of glacial acetic acid is to be 



diluted with 99 volumes of distilled water. 

 *d. Iodine solution : this may be obtained by diluting the 



