100 
METHODS IN PLANT HISTOLOGY 
If the glycerin jelly is well made, it is quite firm and mounts will last 
for a year or two, without sealing; but it is better to seal them with 
balsam. A very good formula is known as Kaiser’s gelatin. It is 
made as follows: One part by weight of the finest French gelatin 
is left for about 2 hours in 6 parts by weight of water; 7 parts of 
glycerin are added, and for every 100 grams of the mixture, 1 gram 
of concentrated carbolic acid. The whole is warmed for 15 minutes, 
stirring all the while until all the flakes produced by the carbolic 
acid have disappeared. Filter while warm through a fine-mesh 
cheese-cloth. 
To make a mount, take a small piece of the glycerin jelly, not 
more than half as large as a grain of wheat—the exact size will depend 
upon the material—warm it until it melts; and then transfer to it 
the material which has already been brought into thick glycerin. 
It is a good plan to touch the material to filter paper in order to 
remove as much glycerin as possible; for the less glycerin the firmer 
the mount will be. The mount may be sealed as soon as it is cool; 
but some prefer to let it stand for a week or two before sealing. In 
any case, it is a fairly firm mount, so that there is no danger of moving 
the cover. 
Everything which can be brought safely into pure glycerin can be 
mounted in glycerin jelly and the preparation is much more stable 
than a glycerin mount. 
