1894 THE MICROSCOPE. 171 



attention. Drs. Thomas Taylor and Theobald Smith rendered 

 assistance. F. W. McAllister and G. T. Sadtler's Sons loaned 

 some microscopes for the purpose. 



QUESTIONS ANSWERED. 



NoTB.— Z>r. S. G. Shanks, of Albany, N. V., kindly consents to receive all sorts of ques- 

 tions relating to microscopy ,iuhethe> asked by professionals or amateurs. Persons of aL 

 g udes of experience, from the beginner upivai d, are ivtlcome to the benefits nf this depar* 

 inent. The questions are numbered for Juture > eference. 



206. How can I breed eels in jMste, for use under the microscope f 

 — Inca. 



Add some old vinegar containing eels to cold, boiled flour 

 paste. A sample of jjaste containing eels may often be found 

 in a bookbinders paste pot. 



207. Where can I yet a work on Bacteria that will give illustra- 

 tions similar to those in the March Microscope, but enlarged so that I 

 can make out the cell walls f — S. A. K. 



Sternberg's Manual of Bacteriology, published by Wm. Wood, 

 Co., price $9,00, will probably supply your needs. 



208. Can you give a good and easily prepared stain for tubercle 

 bacilli f—C. F. 



The Ziehe Carbol-Fuchsin is a good formula : 



Fuchsin (Magenta), 1 part. 



Alcohol, 10 part. 



Solution carbolic acid in water (5 i)er cent) 100 part. 

 Mix and filter. This solutions will keep well. Stain the 

 sputa about 5 minutes cold, or half that time if warmed. Clear 

 up the diffuse staining with a 5 per cent solution of sulphuric 

 acid for •] to 1 minute. 



20y. What is meant by " immunity,''^ or cure-^ produced, by injec- 

 tions of something f — J. A. B. 



Immunity is a protected condition resulting from a first at- 

 tack of a disease, like small pox or measles. A more or less 

 complete immunity is produced by inoculation with cow pox 

 virus, to protect from small pox. At present an animal, say a 

 goat or a horse, is repeatedly inoculated with a pure culture of 



