82 THE MICROSCOPE. June 



ture of the wood, bark, rays, &c. We will make a pres- 

 ent of the slide of spruce to each person sending in an 

 article upon the differences between these four sections. 

 Those articles which are worthy of publication will ap- 

 pear in a subsequent issue of this periodical. 



Bacteriological Work in Medical Science. 



By J. CHRISTIAN BAY, 



DES MOINES, IOWA. 



Until the middle of this century, medical science was 

 in want of an explanation of the nature and origin of in- 

 fectious diseases. The discoveries of Jenner did not 

 have the background that they have now, and it was 

 not until the year 1856, that the first microscopically 

 controlled innoculations were made by Delafond, namely 

 with anthrax. In 1848, the typical germ of this disease 

 had been described by the same savant. Muchlhaeuser 

 (1845,) and Leisering (I860,) were the pioneers on the 

 subject of typhoid fever, in the same direction. 



Infectious diseases are manifested by a series of al- 

 ternate phenomena which distinguish them from all in- 

 toxications. They are, as a general rule, caused by spe- 

 cific organisms (bacteria,) such as tuberculosis, malaria, 

 typhoid fever, recurrens, cholera, yellow fever, etc., and 

 many similiar diseases of animals are manifestations of 

 their life and activity. When not attacking man or ani- 

 mal, they live in organic matter of various kinds ; it is 

 only when circumstances favor their activities that they 

 will attack other organisms. It has been jDroved that 

 many bacteria produce very poisonous substances. The 

 body has to fight the attack made by these, and medi- 

 cine can do but little to help the patient. Outside of 

 the body, bacteria are found living in almost every 

 place in nature where animals can live, and it is impos- 

 sible to avoid coming into contact with them. In all 

 rotten substance, in earth and w^ater, in our clothes and 



