PUBLIC HEALTH BACTERIOLOGY 149 



and filtering all the air through sulphuric acid in the one 

 and potash in the other. Schroeder and von Dusch found 

 (in 1854) that filtration through cotton-wool sufficed, 

 and then Hoffmann, Chevreul, and Pasteur showed that 

 it was quite sufficient to draw out the neck of the bottle 

 and bend it downwards ; and they argued that germs 

 obeyed the laws of gravitation in the absence of wind. 

 Pasteur demonstrated that there was a causal relation 

 between certain lowly organized parasitic organisms and 

 certain diseases of animals and insects. His conclusions 

 were attacked on two grounds : (i) that these organisms 

 were not the cause of disease at all, and (2) that the germs 

 were not specific, i.e., one for each fermentation or disease. 

 The second objection was a forcible one because, so far, he 

 had not been working with pure cultures. The first one was 

 met by the researches of Lemaire, who proved that carbolic 

 acid was hurtful to the life of the higher animals and plants, 

 and that the addition of a small quantity of it to fluids 

 prevented the incidence of putrefaction and fermentation 

 but did not retard the action of diastase or synaptase. He 

 applied the same reasoning to the treatment of wounds, 

 and reduced pus to a minimum and got rapid healing, 

 which results he attributed to the destruction of the 

 microzoa and infusoria by the carbolic acid lotions. Lister 

 saw the great importance of. Pasteur's work, and on it and 

 independent research he built up against considerable 

 opposition the theory and practice of antiseptic surgery. 

 Pathogenic bacteria were also being studied, beginning 

 with Bacillus anthracis, which was first observed by 

 Pollender in 1849, and described by Davaine and Rayer 

 in 1850 as motionless, thread-like organisms and rods, 

 found in the blood taken from animals affected with 

 splenic fever. In 1863 Davaine suggested that these rods 

 were the actual and specific cause of the disease, and in 

 1864 he demonstrated (not rigorously) that malignant 

 pustule and splenic fever were forms of one infection. 

 Confusion was introduced by the revival of the theory of 

 polymorphism in the form that all contagia and miasmata 

 are the products of fungi or algae, and on account of their 

 small size are able to pass through the fine capillary vessels, 

 and that when a micrococcus was found it was only 



