106 THE MICROSCOPE. [April, 



accepted and assigned to a contiguous circuit. The annual dues 

 are one dollar and a good microscopical preparation for Club use. 

 Address R. H. Ward, M. D., No. 53 Fourth st., Troy, N. Y. 



4. Hozv to treat the diatomaceous inaterial sent out by the 

 ^Microscopical yoitrnal f — Ma?ty Subscribers. 



1. Boil the material in clear filtered water, let it cool and set- 

 tle. Carefully pour away the surplus water, add fresh, and boil 

 again. Repeat this boiling and washing until the water remains 

 clear; finally decant the water, leaving the diatoms as dry as pos- 

 sible. 



2. Add half a drachm of strong nitric acid, boil thoroughly, 

 drop a small crystal of bichromate of potash into the hot acid, 

 boil au:ain for several minutes. Add clean water and allow it to 

 settle ; pour away this acid water, add fresh, and repeat this wash- 

 ing until the water remains clear and neutral. 



3. Add a piece of clean soap, about the size of a pea, and a lit- 

 tle water to the diatoms, boil thoroughly, add fresh water, and 

 allow plenty of time for the smaller diatoms to sink through this 

 thick liquid ; pour oft' the soapy water, and continue the washing 

 until the water is absplutely clean. 



Examine a minute quantity of the material w'ith the micro- 

 scope ; if the shells are not clean and bright begin again with the 

 nitric acid and bichromate and follow with the soap as before. 

 Use a four-inch test tube and a lamp of any kind. When boiling 

 have about half a teaspoonful of fluid in the tube ; when washing 

 fill the tube with clean water. Revolve the test tube sharply be- 

 tween the fingers at times during the process of settling, to de- 

 tach diatoms adhering to the sides of the glass tube. Do not 

 hurry the boiling or the settling processes^ Pour oft' the wash 

 water verv slowly so as not to disturb the deposit in the bottom or 

 the test tube. Keep the cleaned diatoms in a small vial of clean 

 water. 



5. Where can I get a slide of volvox globator ? — ATnateur . 

 Various dealers report themselves out of volvox at present. I. 



Percy Blackman, of Sandy Hook, Conn., used to have slides and 

 promises some more the coming July or August. Write to him. 



6. A solitary amateur in Silver City^ N. Mex.., wishes to 

 knoiv hoiv he can work up his enthusiasm .^ .-provide himself 

 with slides^ a?zd keep in touch with kindred spirits ? — f. H. 



Take all the inicroscopical journals and have Carpenter, 

 Stokes, and White in your library. Learn to prepare mounts. 

 Walter White's vegetable preparations (advertised in the Jour- 

 7ial) are beautifully stained sections, usefully mounted, but may 

 be easily remounted on glass slips. The large dealers keep pre- 

 pared packages of unmounted objects — insect dissections, hairs. 



