28 THE AMERICAN MONTHLY [Feb 



ings are all in type and we hope they will be published by 

 Febi-uary. 



Moulds. — Dr. Smith Ely Jelliife of Brooklyn has been 

 carrying- on some excellent investigations. We presented 

 an article last month which we abbreviated from the "Drug- 

 gists Circular", one of our best exchanges and in which 

 there is often something of interest to microscopists. 



Periodical Sale. — With only one insertion of the "M. J." 

 advertisement, the owner has sold to one of our esteemed 

 contributors the 46 bound volumes of the Monthly Micro- 

 scopical Journal and the Royal Microscopical Society 

 Journal for $46, cash on delivery. It is a bargain and an- 

 other such opportunity ma}^ not occur in many months. 



Catalogue. — Send 2-cent postal card to Dulau & Co., 37 

 Soho Square, London, for 30-page catalogue of books and 

 papers relating to microscopy and for sale by them at net 

 pi-ices named in this pamphlet. Some of the prices are 

 very high but they have a really wonderful collection of 

 microscopical publications. 



Objects.— Suter, 10 Highweek road, Tottenham, Lon_ 

 don, sends free a catalog-ue of 50,000 choice objects. He 

 buys collections and sells cabinets. 



Most Powerful Objective. — The best yet made is the 

 1-10 inch mono-bromide of napthaline immersion lens, 

 numerical aperture of 1,60 made by Zeiss. Its work is lim- 

 ited to resolving a detail more than 1-8000 of a millimeter 

 (.000,005 of an inch) in width. 



Leprosy. — The International Congress on Leprosy has 

 declared that this disease is due to a bacillus discovered by 

 Hansen in 1871, that no other animal than man suffers 

 from it, that it is contagious but not hereditar}-, and that 

 isolation is desirable. 



Vaccination. — Small granular ameboid bodies are found 

 in the blood of vaccinated ehildren. Similar amoeba have 

 been found in blood of vaccinated monkeys. They have 

 a diameter of one-third that of a red blood-cell. 



