722 DISTRIBUTION AND HABITAT OF THE BACTERIA. 



them or in the contaminated soil. We must undoubtedly 

 give up this view, since we have become better acquainted 

 with the conditions of life of the pathogenic bacteria ; 

 and we cannot now see in a contamination of the soil 

 such a great and immediate danger of infection as for- 

 merly, especially when the water required for household 

 purposes is not taken from this soil, but is conducted 

 Significance from a distance by a system of pipes. Of course, how- 



of contamina- . J . i A v 



tionofthe ever, it is very desirable for other reasons to keep the 

 soil pure, and this is attained at the same time and in 

 the most complete manner by those methods which keep 

 prominently in view as rapid a removal of all pathogenic 

 agents as possible from the dwelling-house. The neces- 

 sity for and the sanitary effect of drainage thus remain 

 the same, and it is only the basis on which the precau- 

 tions are taken which is altered in accordance with the 

 more recent views. 



infection as The profession and business of the individuals also in 



profeTsionand manv wa js aid the spread or the reception of pathogenic 



occupation, bacteria. In former times, for example, the infective 



diseases of wounds were undoubtedly often carried by 



physicians who did not at that time hesitate to examine 



the infected wounds of one patient and the fresh wounds 



of another with the same imperfectly cleansed finger. 



infection by Even now infection is frequently carried by the clothes 



and liands of tllose medical men who do not rightly 

 estimate the dangers of infection. In like manner mid- 

 wives, to whom is almost entirely to be ascribed the 

 transmission of puerperal fever, nurses, washerwomen, 

 old clothes men, rag-collectors, &c., very often lead to 

 Opportunities the further spread of infective agents.-' We only require 

 to specially mention further the manifold possibilities of 

 infection to which children are wont to expose them- 

 selves ; how they cover their hands now with the soil of 

 dirty courts, now with the water of gutters, and the most 

 various objects rich in bacteria, and then the next mo- 

 ment place them in their mouths, or eat their food with 

 their dirty hands. It is difficult to understand how 

 when a child becomes ill from typhoid fever, diphtheria, 

 &c., the majority of doctors, in spite of these dangers of 



