1897] MICROSCOPICAL JOURNAL. 27 



any particular position may be recorded and found ag"ain 

 easily. The object is in a simple carrier close to the sur- 

 face of the stage. The mechanical stag-e can be fitted to 

 any stagfe if the location of the clip-holes and center of the 

 stag-e is known. It is sold by Zentmayer for $16.00. 



MICROSCOPICAL MANIPULATION. 



To Distinguish Guaiacol from Beechwood Creosote. — 

 Mr. Vreven utilizes the following- method for disting-uish- 

 ing- beechwood creosote from liquid guaiacol: He places a 

 few drops of the substance under examination in a test 

 tube and adds 2 or 3 drops of ether and I or 2 drops of con- 

 centrated nitric acid or of concentrated hydrochloric acid 

 and ag-itates the mixture. There is first of all a reddish 

 brown coloration produced in the ethereal layer. After 

 spontaneous evaporation of the ether there remain oily 

 drops if the substance on examination is creosote, or if it 

 is liquid g-uaiacol the residue is in the form of crystals. 

 Sometimes crystals are not produced even if the substance 

 examined is liquid g-uaiacol unless the residue is ag-itated, 

 but upon ag-itation the crystals appear immediately. Under 

 the same conditions carbolic acid also yields crystals, but 

 their form does not at all resemble the form of crystals 

 produced by g-uaiacol, the crystals of the latter consisting- 

 of needles ag-gregated in the form of stars which are very 

 easily disting-uished under the microscope. — ^American 

 Druggist. 



New Method of Purifying Water. — The French Acad- 

 emy of Sciences appears to indorse the new method of 

 purifying- water by calcium permanganate and mang^anese 

 dioxide. According- to this method, the calcium perman- 

 ganate coming- in contact with organic matter and micro- 

 organisms, destroys them and decomposes itself into oxy- 

 gen, mang-anese oxide and lime Then, to carrv off the 

 surplus of permang-anate and complete the purification, 

 the water is poured over manag-anese dioxide; oxyg-en in 

 the nascent state is thus freed and it burns up any remain- 



