NATURAL SCIENCES OF PHILADELPHIA. 15 



at a means of preserving permanently objects suitably prepared for scientific 

 observations, as to be able to prepare them for such observation without 

 reference to their preservation. Since we can only hope to arrive at accurate 

 conclusions by repeated study, not by one, but many observers, this can only 

 be done by having the object suitably prepared and permanently preserved. 



The formula for making glycerine jelly is as follows : 



Take one package of Cox's gelatine, wash repeatedly iu cold water, then 

 place in a vessel and add sufficiently cold water to cover it. Allow it to soak 

 an hour or two, pour oif superfluous water, add one pint of boiling water, place 

 vessel on fire and boil for ten or fifteen minutes. Remove from fire, and when 

 cool, but still fluid, add the white of an egg, well beaten, replace ou the fire 

 and boil until the albumen of the egg coagulates. Strain while hot through 

 flannel, and add an equal portion by measurement of Bower's pure glycerine, 

 and fifty drops of carbolic acid in solution ; boil again for ten or fifteen 

 minutes, and again strain through flannel, place in waier bath, and evaporate 

 to about one-half, then filter into two oz. broad-mouthed vials. (Cotton is the 

 best filtering medium.) 



To use the jelly in mounting objects : — Place the stock bottle in a small jar 

 of boiling water; when it becomes fluid, asufiicient quantity must be removed 

 to the slide (previously warmed), with a glass rod; the object, (previously 

 soaked for some hours in equal parts of glycerine and distilled water, with a 

 few drops of alcohol,) is to be placed in the drop of fluid jelly, a cover applied 

 and slight weight placed upon it to exclude superfluous jelly. When cold, 

 clean off the slide with a knife and wash in cold water ; finish with a ring of 

 gold size or shellac varnish. 



Note. — Dr. Carpenter cautions against use of Glycerin with objects of a 

 calcareous nature, as it is a solvent of carbonate of lime. 



Mr. Chas. Bullock remarked that it is important to give the 

 gelatine frequent washings previous to use, to remove traces of sul- 

 phuric acid, which invariably remain from the process employed in 

 its preparation. 



INlitchell W. McAllister, S. Fisher Corlies and Dr. J. G, Richard- 

 son, were this evening chosen members of the Department. 



Prof. 0. W. Holmes, of Boston, was chosen a corresponding 

 member. 



