1900] MICROSCOPICAL JOURNAL * [149 



function of which is quite unknown. In addition to this col- 

 lection there were two specially well-mounted slides of 

 Stephanoceros and Floscularia to show what can be accom- 

 plished in the way of preserving- rotifers. 



MICROSCOPICAL NOTES. 



Klondyke. — The Geolog^ical Survey of Canada has issued 

 a valuable report on the gfold fields of the Klondyke reg"ion. 



Prevention of Mould. — Collections of microscopic mate- 

 rial kept in damp places, or in a moist atmosphere, are very 

 liable to mould, and under such conditions it is difficult to 

 avoid this evil. Carbolic acid is recommended, but Mr. 

 Ashmead, who has kept a larg-e collection in the moist cli- 

 mate of Florida, has found the use of napthaline much 

 more satisfactory. Mr. H. H. Smith, who has had more 

 extensive experience in the tropics, prefers the carbolic 

 acid. Mouldy specimens may be cleaned by washing- with 

 carbolic acid applied with a fine camel's hair brush. — Pop- 

 ular Science. 



Microscopic Crystals Etched. — The forms of micro- 

 scopic crystals may be accurately reproduced on g-lass by 

 etching with fluoric acid. Interesting and beautiful effects 

 may be obtained by crystallizing various salts in a thin lay- 

 er on a glass slip which has been well warmed to prevent 

 the crystals from dissolving-, and then exposing- the glass 

 to the action of the vapor of fluoric acid for three to five 

 minutes. Hydrofluoric acid can be evolved from flour spar 

 wet with sulphuric acid in a leaden dish. The fumes must 

 not be breathed. — Popular Science. 



Lloyd Library Bulletin.— This expensive and exquisitly 

 made volume (No. 1, 1900) relates to Botany, Pharmacy and 

 Materia Medica and includes a reprint of Benj. S. Barton's 

 Essays of 1798 and 1804, also a portrait of the author, and 

 his biography. To be obtained from Lloyd Library, Cin- 

 cinnati, Ohio for $1.00. 



WANTED. — To exchanga diatomacaous earfh. C.W.Smilay. 



