W. H. GILBURT ON THE STAINING OF VEGETABLE TISSUES. 305 



some very interesting slides for the microscope ; but this is not 

 enough for those who seek improved methods of preparation, in 

 order to facilitate their studies. This being my feeling, I have 

 during the past year endeavoured, by somewhat modifying the 

 process, to render it more valuable ; and with some success, so far as 

 leaves and petals are concerned, the part of the subject to which I 

 have given the greatest attention. Not that the modification effected 

 is very great, but in this, as in many other things, a slight alteration 

 may make a considerable difference in the result. 



In employing these methods, let it not be supposed that there are 

 many difficulties to be overcome, or great manipulative skill required ; 

 on the contrary, although the instructions, when read, appear compli- 

 cated, yet when once they have been worked through, nothing can 

 well be easier, or, when mastered, prove more helpful, or give a 

 greater interest in the study of vegetable histology. By their use 

 we can obtain an insight into structure, such as can be had by no 

 other means. 



The staining fluids which I have used with success have been 

 alcoholic solutions of blue and magenta anilines. 



The magenta solution is made by dissolving a quarter of a grain 

 of the crystals in one ounce of alcohol. 



The blue by dissolving one-sixth of a grain of the crystals in one 



ounce of alcohol, to which has been added, two drops of nitric acid. 



Both solutions should be filtered when first made. 



I have tried two or three makes of blue, but find none so good as 



that recommended by Dr. Beatty, viz., Nicholson's soluble blue pure. 



Finding- it difficult to procure these aniline colours in crystals, 



I at first used Judson's dyes, and found them answer very well, 



especially for stem sections. Good solutions of these will be made 



by adding half a drachm of the dye as sold, to one ounce of alcohol, 



and to the blue two drops of nitric acid, as in the other solution. 



If Judson's dyes are used, the blue solution will occasionally 

 require filtering. 



In order to prepare tissues for staining, it is first necessary to 

 bleach them. This may be effected in the case of soft green stems, 

 in alcohol ; the use of which, where it will discharge the natural 

 colour, considerably abridges the process. It also has this further 

 advantage — by its use most of the cell contents are preserved, such 

 as starch, chlorophyll granules, &c, and the nucleus, where it exists, 

 can be seen after staining. 



