272 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



One of these latter gave an average one millionth of an inch 

 smaller than the smallest average for human blood ; all the 

 others gave averages larger than the smallest for human 

 blood ; and the doctor states that, in his opinion, no one 

 could have told from the examination of this drop of blood 

 whether it belonged to the guinea-pig, the dog, or man. 

 Monthly Microscopical Journal^ September^ 1876. 



AIR GERMS. 



The analyses of the air and other experiments made by- 

 Pasteur for the purpose of investigating the doctrine of 

 spontaneous generation have demonstrated that the germs 

 of inferior organisms, micrococci, bacteria, etc., are every 

 where present in the air. In a hospital the air contains a 

 great number of these elements, and, in addition, certain 

 special bodies, such as pus globules and spores of epiphytic 

 parasites, which emanate from diseased organisms, and ow- 

 ing to their volatility after desiccation are susceptible of 

 hovering in the atmosphere. One square meter of the wall 

 in the surgical ward of La Pitie having been washed, after 

 neglect of two years, the liquid expressed from the sponge 

 (about thirty grammes) was examined immediately after- 

 Avard. It was black, and showed micrococcus in large amount, 

 bacteria, epithelial cells, pus globules, red globules, and ir- 

 regular blackish masses and ovoid bodies of unknown nat- 

 ure. More recently Dr. Esbeth, of Zurich, has, says the 3Ied- 

 icalliecordj found, by the aid of the microscope, in the sweat 

 from the face, axilla, breast, and thigh, enormous numbers of 

 bacteria. They appear to have originated from minute bod- 

 ies found upon the hairs in the mentioned regions, forming 

 little nodules on them, and appearing as accumulations of 

 micrococci. 



POLARIZING CRYSTALS. 



Mr. C. Merriman ogives the foUowinsj hints on " Polarizinc: 

 Crystallizations." All solutions must be in distilled water, 

 and carefully filtered. Solution of gum arable must be add- 

 ed to the crystalline solution until the drops will dry on the 

 slide without crystallizing. Then the drop on the slide is to 

 be held over steam until one or more points of crystallization 

 appear, then at once dried over an alcohol lamp; then held 



