THE MICROSCOPE. 31 



Prof. Tait states that a flash of lightning is of such short dura- 

 tion that the eye could not possibly follow its movements. When a 

 flash appears to start from one point and extend, it is because the 

 spectator sees first that part of the flash of light toward which his 

 eye is directed, and the rest of the streak is appreciated later by the 

 less sensitive portions of the retina. — Ex. 



Formation of Vinegar by Bacteria. — E. Wurm has investigated 

 this matter, and his results prove, without doubt, that an active for- 

 mation of vinegar from alcohol is obtained by means of Macoderma 

 aceti (Bacterium mycoderma — Cohn), thus supporting Pasteur's 

 views. — Science. 



Organisms in Beet Sap. — The bodies known as " frog-spawn," 

 which make their appearance after a time in the sap of the beet root, 

 prove, on microscopic examination to be a species of bacterium, 

 called by L. Cienkowski, Ascoccus Bilrothii. — Ex. 



It has been found by several microscopists that the cause of 

 whooping-cough is a peculiar fungoid growth, which first germinates 

 under the tongue and then pervades the air passages. Quinine is 

 found to be a valuable antidote by virtue of its well-established 

 power to destroy microscopic vegetable organisms. — Ex. 



Thin glass covers. — A microscopist has taken the trouble to 

 measure the thin glass covers purchased at a first class house, and 

 found that in two ounces but one third were correct in their thick- 

 ness Y^ to ^^ of an inch, two-thirds belonging to a cheaper grade. 

 Only one sixty-eighth were -^^-^ of an inch in thickness, the majority 

 being only fit for opaque objects. — Ex. 



Poisoned by Postage Stamps. — We hear of a young man belong- 

 ing in this city who has recently been quite severely poisoned by 

 corrosive sublimate contained in the mucilage upon postage-stamps 

 which he moistened with his tongue as he stuck them upon some 

 200 envelopes. The poison had been taken in sufficient quantities 

 to produce violent pains in the abdomen and limbs, and other symp- 

 toms of quite an alarming nature. We believe the young man was 

 confied to his bed for some days. — Keene (N. H.) Sentinel. 



