1896 THE MICROSCOPE. 15 5 



to a friend. The novice displayed his acquisition. The 

 friend exhibited a balsam mount of the same frustule un- 

 der a fine Spencer 1-6 objective. The Spencer resolution 

 seemed to be cast entirely in the shade. It developed, 

 however, that the diatom under the foreig-n lens was 

 mounted in naphthaline monobromide. When the balsam 

 mount was placed under the foreig-n lens the Spencer lens 

 resumed.its well-deserved g-ig-antic proportions. Moral: 

 A novice should never purchase a fine lens without the ad- 

 vice and inspection of an expert. 



QUESTIONS ANSWERED. 



NoTB.— Z?r. S. G. Shanks, of Albany, N V., lundLy cuice'its to receive nl.' so'ts o' </w^ 

 fions relating to mtcrosco/>y,tvketlter asked I'y professionals or amateurs. Persons 11/ .u 

 g tides 0/ experience, from the beginner tip7uard, are 7uelcome to the benefits 0/ this depa- ' 

 inent. The questions are numbered Jor Juture reference. 



Q. 243. — Where may be obtained the substance "Gum 

 Thus"? F. F. E. 



A. An order placed with Wm. Schieffelin & Co., Drug-- 

 g-ists, New York, will probably bring Gum Thus. 



Q. 244. — What is the name of the best book g-iving- 

 methods of staining-, especially double staining for both 

 plant and animal specimens? F. F. E. 



A. The methods of Microscopical Research by Arthur 

 C. Cole, or Practical Methods in Microscopy by C. H. 

 Clark, will be found useful. 



SCIENCE-GOSSIP. 



The Poultice a Hot Bed of Bacteria. — Dr. J. C. Biddle, 

 in the Lehigh Valley Medical Mag-azine, calls attention 

 to the abuse of poultices, and says he has seen many cases, 

 where the application of a poultice has done irreparable 

 damag-e. He has seen many cases w^here poultices were 

 applied to abrasions, contusions, sprains, simple and com- 

 pound fractures, until the skin and underlying tissues 



