108 THE AMERICAN MONTHLY [May, 



movements, from their being found by Dr. Robert Brown to be asso- 

 ciated witii all minute particles in suspension in a fluid, whether they 

 be organic or inorganic in their nature. Nothing is more likely to lead 

 the student astray than to see these movements and not be awai^e of 

 their character, such as one would be led to imagine he had discovered 

 living elements where only physical causes are at work. With a view 

 to familiarize him with their appearance, it is only necessary to rijb a 

 little gamboge on a slide in some water, and on examining a thin layer 

 of this with a quarter-inch objective the particles of gamboge will be 

 seen dancing round each other all over the field of view. The late 

 Stanley Jevons had a very pretty way of exhibiting these phenomena. 

 A shallow trough was to be made by uniting two square cover-glasses 

 by three of their edges, and a small quantity of kaolin mixed with water 

 was to be placed in it and allowed to subside till the boundary line be- 

 tween the surface of the deposited kaolm and the water was well de- 

 fined. If now a small drop of solution of soap be allowed to run 

 down one side of the trough and spread itself gently and without dis- 

 turbance over the surface of the kaolin,, although no active movements 

 of its particles will take place directly, yet, in a short time, the whole 

 surface will be seen in a state of lively vibration, owing to the Brownian 

 movements being set up by the slight addition to the specific gravity of 

 the water due to the soap. The movements are not attributable to evap- 

 oration, because they may often be observed in closed cavities, but may 

 be influenced by electrical conditions, and in this direction we must 

 seek for their origin. 



The Long Island College Hospital. — We have received the an- 

 nouncement of this Hospital for 1891, and desire to call attention to the 

 following changes : 



(i) The regular course of lectures will hereafter be six months in 

 duration. 



(3) Three courses of lectures will hereafter be required for gradua- 

 tion. 



(3) Joshua M. Van Cott, jr., M. D., has been appointed Professor 

 of riistology and Pathological Anatomy vice Frank Ferguson M. D., 

 who has resigned. 



(4) The medical class of the present year numbered 250; the grad- 

 uating class 82. 



(5) 20,830 patients were under treatment in the Hospital and dispen- 

 sary during the year 1890. 



Dr. Simpson, of Calcutta, has exhibited some cultivations on steril- 

 ized potatoes of organisms obtained from the water of Tolly's Nullah. 

 In them were growths ol Aspergillus oldlmn ^\\A Perilclllhim^vi\\\z\\, 

 to the naked eye, presented the appearance of a white flufly down in- 

 terspersed with green and blue spots and little dew-like drops of 

 moisture. Distinct from these were other growths of a yellow, sal- 

 mon, and brown color, which, under the microscope, proved to be 

 groups of various kinds of Bacteria. These show what luxuriant 

 growths of organisms could be got on sterilized potatoes, and how, 

 by this simple method, students could study \\\q ftuigl ?iwd. bacteria., and 

 could thus add to our knowledge of the Thallophytes., a group the 

 importance of which, in the economy of Nature, is becoming more 

 evident the more they are studied. 



