ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 535 



water, which keeps the jelly under the cover hard. The slides are 

 then dried with a towel or blotter, and finished with a balsam ring or 

 any other cement desired. 



The advantages of this method are that it obviates the necessity 

 of the previous preparation of cells for objects of considerable thick- 

 ness, and it seems to present most of the advantages of a fluid mount 

 without its difficulties. If the slide is properly dried before finishing 

 with balsam, no cloudiness appears, and the slide cannot be distin- 

 guished by inspection from a balsam mount, while there is much less 

 distortion, loss of colour, &c., in the jelly than in the balsam solutions 

 usually employed. Mr. Seaman has found no reason in ten years' 

 experience to doubt that slides mounted in this way will be 

 permanent. 



Mounting Starches.* — The Editors of ' The Microscope ' | de- 

 scribe their method of preserving starches as follows : — 



'• It is necessary first to have some aniline blue staining fluid, 

 which we make after the formula given by Beale ; — 



Soluble aniline blue ^ grain. 



Distilled water 1 ounce. 



Alcohol 25 drops. 



A mixture is made of equal parts of glycerine and water, to which 

 is added a very little acetic acid, only two or three drops to the ounce. 



To this mixture of slightly acidulated dilute glycerine is added 

 the aniline blue staining fluid until the whole mixture is of a decided 

 blue colour. 



A drop of this mixture is placed on a glass slide and some of the 

 starch to be mounted is dusted over the top. This dusting can be 

 done to the very best advantage by touching the starch with a camel's- 

 hair brush, and then slightly shaking the brush over the drop of 

 coloured glycerine. 



The starch soon sinks in the mixture, and the cover is applied. 

 This method of dusting the starch is much better than stirring it in 

 the mixture with a fine needle, which almost invariably results in an 

 admixture of air. 



After the cover is applied it is pressed down quite firmly against 

 the slide, and all excess of the glycerine carefully removed. The 

 slide is then transferred to the turntable, and a thin layer of dammar 

 or balsam in benzole placed around the border of the cover. This 

 soon hardens, and in a day or two we can finish with the white zinc 

 or Brunswick black or other cements. 



The effect of thus mounting the grains of starch is this : — the 

 grains themselves have not taken the staining in the least, neither will 

 they ever take it ; they retain their natural appearance, surrounded 

 everywhere by the blue glycerine, and the effect is most beautiful. 



Specimens are in the Editor's possession that were mounted over 

 a year ago in this way, and they are as perfect as the day they were 

 prepared." 



* ' The Microscope,' i. (1881) pp. 13-M. 

 t See this Journal, mfra, p. 546. 



