238 THE AMERICAN MONTHLY [October, 



A seemingly disintegrating tendency has been felt by the American 

 Association caused by the pronounced advantages securable in separate 

 organizations, but these advantages we believe may be secured without 

 serious injury to the parent association, if wise counsels prevail. 



Let, then, the American Society of Microscopists arrange to begin its 

 next meeting at Lidianapolis on the Tuesday in August which marks 

 the close of the American Association, and if this proves impracticable 

 then come as near to it as possible, both in time and place. 



EXTRACTS FROM CORRESPONDENCE. 



Modified Crystals of Cupric Sulphate. By Wm. N. Hastings, 

 Rochester, N. H. 



The following method has proved quite successful in producing, among 

 other beautiful forms, the vortical rosettes figured by Carpenter in 

 " The Microscope and its Revelations." 



A drop of saturated aqueous solution of sulphate of copper is placed 

 upon the slide and rubbed with the finger until a thin but perfect film 

 adheres to the surface. Evaporate over the lamp. No crystals should 

 then be visible. Allow it to cool and breathe upon it. Examine with 

 low power. Further breathing will further modify the crystals. The 

 amount of moisture and thickness of the film will determine the forms 

 produced. 

 Dissolving Apparatus. By Dr. H. P. Nottage, Boston, Mass. 



I have invented an efficient and simple apparatus for producing a 

 dissolving view with a single lantern, and am making application for 

 letters-patent. This machine produces an entirely new and novel effect, 

 and dissolves a picture just as efficiently as an expensive double lantern 

 dissolving apparatus. In all previous inventions for use with a single 

 lantern the screen is left in darkness while the picture is being changed, 

 but with this apparatus it is covered with light all the time. 



Sectio7ts for Practice in Staining. Bv W. G. Crosbv, Canandaigua, 

 N. Y. 

 I would suggest that a series of vegetable and wood sections be pre- 

 pared by some one suitable for the delightful pastime of double and 

 single staining by amateurs who have no microtome, and whose time 

 does not permit them to seek out and prepare the material. I am con- 

 fident such preparations would meet a ready sale. Perhaps such sec- 

 tions may even now be procured, but I do not know where. If so, my 

 pupils and the members of our society would like the information. 



MICROSCOPICAL SOCIETIES. 



St. Louis Club of Microscopists. 



Tuesday evening. Angiist 6. — The name of C. C. Paris was pro- 

 posed for membership. 



J. B. Whinerv made a report on the examination of powdered acacia. 

 Out of seven samples, one was found with starch. He will do further 

 work on the same subject. A member said that rice starch has been 



