244 THE POPULAR SCIENCE MONTHLY. 



have courage to kill a bird in hunting ; but, in making experiments, 

 I have no such scruples. Science has a right to invoke the sovereignty 

 of the end." 



What he has done, M, Pasteur regards as only the beginning of 

 what is to be accomplished in the same line. " You will see," he has 

 sometimes said, " how this will grow as it goes on. Oh, if I only 

 had time ! " 



-♦♦♦- 



CLEAK DKmKmG-WATEK. 



By EDWIN J. HOWE, M. D. 



AMONG the subjects that claim the study of the sanitarian, 

 there is none that has a closer relation to public health, and 

 hence none more worthy of careful investigation, than the water we 

 drink. Receiving it, as we do, from varied sources — from spring, 

 well, brook, or river — its character varies greatly ; and, while in its 

 purity bringing with it refreshment and health, in a polluted condi' 

 tion it too often carries in its wake disease and death. 



The study of sanitary science during the last few years has demon- 

 strated beyond a doubt that many severe epidemics have arisen from 

 the use of impure water, as the reading of Witthaus, Parkes, Buck, 

 Flint, Pavy, or other writers on the subject, will clearly prove. 



When we remember that water has greater solvent properties than 

 any other liquid known, we can readily understand how it often be- 

 comes such a disease-spreading medium. Besides carrying with it 

 vegetable and organic impurities in suspension, it dissolves many of 

 those that are the most subtile and dangerous to the human organ- 

 ism. The dangers of drinking impure water may best be presented in 

 a few quotations from well-known authorities. 



Pavy, in "Food and Dietetics," says : "Water has much to an- 

 swer for in the causation of disease, ... It" (polluted water) "is 

 acknowledged to be one of the common causes of dysentery, and has 

 been alleged, when derived from a marshy district, to be capable of 

 inducing malarial fever and its concomitant, enlargement of the spleen. 

 . . . Typhoid has been frequently communicated through the medium 

 of water. Milk, adulterated with polluted water, has been the cause 

 of serious outbreaks of fever." Pai'kes, in his " Manual of Practical 

 Hygiene," shows that the baneful effects of polluted water were known 

 to the ancient Greeks. Hippocrates, who was born 460 b. c, asserts, 

 " The spleens of those who drink the water of marshes become etilarged 

 and hard." Parkes considers typhoid, cholera, scarlet fever, and diph- 

 theria, and some forms of skin-disease, " likely to be propagated by 

 means of water." 



Polluted water that has been frozen, though improved by the 

 freezing, does not become innocuous. "Ice and snow may be the 



