82 THE AMERICAN MONTHLY [May, 



Dissolve one part of Marseilles soap in forty parts of water (raiti or dis- 

 tilled) , which may be warmed. 



When cool, filter through very porous filter paper and add Price's glycer- 

 ine in the proportion of eleven parts of glycerine to fifteen parts of the soap 

 solution. 



Shake thoroughly and allow the solution to stand for seven days where the 

 temperature will not fall below 67° Fahr. Then cool to 37° Fahr. and filter, 

 keeping a bottle of ice in the funnel. The first parts filtered should be refil- 

 tered, using very porous filter paper. 



Halbrook's brown oil silk soap, or his Gallipoli soap, and Sheering and 

 Glatz's glycerine work very well. 



Long standing and decantation from sediment may take the place of the 

 second filtration. After all the trouble, the mixture may not give very good 

 results. 



An excellent soap-bubble solution may be formed by a compound of oleate 

 of soda and pure glycerine. Bubbles two feet in diameter may be blown, and 

 bubbles have been kept, under glass, for 48 hours. 



A good and easily prepared solution may be made by shaving four ounces 

 of Marseilles, or, better, of pure palm oil soap, and placing it in a quart or 

 distilled or rain water. Shake until a saturated solution is formed and let it 

 settle for a few hours. The solution should then be clear. If otherwise, pour 

 oft' the water, and add fresh water to the same soap and try again. To the clear 

 solution add about one-half the quantity of glvcerine that is absolutely pure. 

 The presence of the least quantity of acid in the glycerine is fatal to good re- 

 sults, and, therefore, it is recommended that for any soap-bubble solution the 

 ingredients be the best and purest obtainable, and that chemically pure glyc- 

 erine be used. It costs about 75 cents per pound. 



Instaiitaueous Mounting in Farrant's Gum and Glycerine Medium.* 



By R. H. ward, M. D., 



TROY, N. Y. 



For facility of use too much can scarcely be said in favor of Farrant's Gum 

 and Glycerine Medium. It may be inferior to glycerine jelly for mounting 

 sections that are large and not liable to be injured by heating, as both are 

 doubtless inferior to Canada balsam for objects that are not too transparent in 

 the latter, or that can be rendered sufficientl}' conspicuous by staining, and 

 that can be dehydrated and transferred to the balsam without injurious modi- 

 fication of structure. But it answei's excellently for a very large variety of 

 specimens, both animal and vegetable, that can be studied to advantage in 

 water or in glycerine, and that, in the former case, can be transferred to a 

 dense mucilaginous medium without destruction by exomose. For such ob- 

 jects it very nearly accomplishes the paradox of enabling one to mount spec- 

 imens without the trouble of mounting them. 



Those who prepare objects for the trade, and students who are working in 

 the laboratories as learners, make a business of the hardening of objects, the 

 cutting of sections, the handling of reagents, the selection and manipulation 

 of varnishes, etc. ; and many amateurs and everj professional admirers take 

 pleasure in imitating, and often excelling them in this recreative work. 



Many professional microscopists. however, find their time filled with other 

 engagements. Objects almost without number are examined for purely 

 scientific investigation, or for sanitary, economic, medical, or legal purposes, 

 and then are inevitably thrown away for vs'ant of the time required, but not 

 just then available, for mounting them. Such objects are often examined in 



* From a paper refid at t))^^ Mjprpscopical Section of the Troy Scientific Association. 



