90 THE MICROSCOPE. June 



phuric ether, he has recently been able to pcrserve human 

 blood in the same manner. For several weeks, he states, 

 he has kept, in ordinary test tubes, lig-htly corked, human 

 blood and on examination he finds it absolutely unaltered. 



Examination of Spots on ^Vood for Spermatozoa. — Some 

 time since we published a process accredited to Schu- 

 maker-Kopp, for facilitating- this sometimes very difficult 

 examination. Since then, having- to make severalexamina- 

 tions, we have found the following modification to answer 

 better than the original. With a sharp knife remove the 

 surface of the spot, either by scratching or by cutting a 

 delicate sliver. Let the debris fall into a thin nearly flat 

 watch crystal, and cover them with dilute water of am- 

 monia for several hours, occasionally moving the material 

 about with a dissecting needle. After standing for from 

 four to six hours, carefully decant or draw off the liquid 

 with the supernatant debris, leaving the precipitate on the 

 watch-glass. To the latter add a little distilled water and 

 let stand until the precipitate has again subsided. Pour 

 off all of the water that can be removed without danger of 

 disturbing the precipitate, and to the latter add a drop or 

 two of picric acid solution or aniline violet. Stir up and 

 remove the material with a pipette to slips, putting a drop- 

 let on each slip. Examine, a slip by dropping a cover glass 

 on the liquid. Sometimes the spermatozoa can be detected, 

 but if not, let the liquid dry on the slip spontaneously, and 

 then examine, either with glycerin or with dammar. Very 

 rarely an entire spermatozoan may be found, but usually 

 (where they are present at all) they will be found in a 

 mutilated or broken condition. — National Druggist. 



Bacteria in Oysters. — An outbreak of typhoid fever 

 amongst those who attended the Stirling County Ball 

 in October, 1895, g-ave rise to the suspicion that the oys- 

 ters supplied on that occasion were the carriers of infec- 

 tion, but Dr. Chalmers, one of the Glasgow medical offi- 

 cers of health, investigated the matter and concluded that 

 the cause of the enteric fever infection was not conveyed in 

 the oysters. A bacteriological examination of oysters from 



