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ings ; dried leaves will bleach sooner than fresh gathered ones. 

 Having bleiifhed some leaves (the time it takes to do this vary- 

 ing very much), they must be well waslied in -warm water, in 

 basins or i^ie dishes, changing this often, for about two days ; 

 they should then be well brushed with soft camel hair brushes, 

 and I often find it of use to put them into acetic acid and water 

 for about a minute, before the final washing, but acids must be 

 very cautiously used or the crystals may be dissolved. The 

 leaves are tlion ready to go into either of the following dyes. 

 The carmine dye is prepared partly according to Dr. Beales' 

 formula, viz. : — Carmine, 20 grains ; strong liquor ammonia, ^ 

 dram ; pure water, 4 ounces. The carmine is heated in a test 

 tube with the ammonia till dissolved, and then added to the 

 water in a bottle, well shaken and left to settle or be filtered. 

 The dye should smell strongly ammoniacal. Sections are soon 

 dyed in the above, but leaves often take several days or a week. 

 Sections of the India rubber plant leaf or of the common fig, 

 dyed in carmine, will show the stalked ci-ystals, called cystoliths, 

 very nicely ; pieces of the leaves of fig, hop, nettle, wall pelli- 

 tory, wych elm, dyed, mil show the cystoliths when viewed from 

 above or below. I generally mount two leaves or pieces on the 

 same slide, one with the superior and the other with the inferior 

 surface uppermost. The logwood dye is prepared according to 

 the prescription in " Rutherford's Histology" : — A. Make a 

 saturated solution of calcium chloride in 70 per cent, alcohol, 

 and then add alum to saturation. B. A saturated solution of 

 alum in 70 per cent, alcohol. C. Add A to B in the proportion 

 of one to eight. D. A barely alkaline saturated solution of log- 

 wood in water. Add D to C till a deep violet coloured dye is 

 obtained. I make D by boiling logwood chips with water and a 

 little potash, then filter. The leaves and tissues may bo im- 

 mersed in this from the last wash water, and will be dyed in 

 about the same time as the ones in carmine. Leaves when dyed, 

 either with carmine or logwood, must be taken out and well 

 washed and brushed in about two wash waters, then dip those 

 dyed in carmine into acetic acid and water for about a minute ; 

 those dyed in logwood in alum and water, then wash again. The 

 remaining oj^erations will be described further on. I also use a 

 blue dye made by pouring si.x or eight drop.s of Judson's analyne 

 blue into an ounce of methylated spirit, shaking and filtering. 

 Leaves and sections to be dyed in this must be soaked in methy- 

 lated spirit for about a day, after being taken out of the last 

 wash water. After dyeing they must be washed and brushed in 

 methylated sjiirit. Leaves generally require to be kept in this 

 dye for several days. Leaves and sections, after undergoing 

 these operations, may either be mounted in Deane's gelatine 

 medium or in dammar or balsam dissolved in benzole. I like to 



