COLLECTION OF SPECIMENS 173 



and have also made numerous experiments, with 

 a view to discover some way of obviating such a 

 catastrophe in future. I venture to give here 

 some of the results of these observations and 

 experiments. 



In the first place, I have found the following a 

 very good recipe for making glycerine jelly : 

 Take two ounces (by weight) of the best gelatine 

 (that sold by chemists as "invalid" gelatine by 

 preference) ; soak it in six ounces (also by weight) 

 of water until it swells this takes about forty 

 minutes ; place the vessel containing the gelatine 

 and water (a large-sized jam-pot, provided with a 

 tin lid, answers the purpose admirably) in a 

 saucepan of water, and heat over a slow fire until 

 the gelatine melts, which it will do in about ten 

 minutes. Now let the gelatine cool, and, while it 

 is still liquid, add the white of one egg, and mix 

 well. Replace the vessel in the saucepan (with 

 the lid on), and boil for fifteen minutes, until the 

 gelatine becomes thick with the coagulated albu- 

 men ; add six ounces (again by weight) of pure 

 glycerine, and twenty-five drops of carbolic acid, 

 and mix well ; strain, by means of a funnel and 

 filter-papers, before the fire, and a clear, pale 

 yellow jelly should be the result. The filter-paper 

 requires changing occasionally, as it gets clogged 

 if used for too long. 



It will be seen that the above recipe includes a 

 small quantity of carbolic acid ; this, it is needless 



