i 7 o THE POPULAR SCIENCE MONTHLY. 



some variety of nutritious food than could the lord of the mid- 

 dle ages. 



Next, the invention of machinery has so increased the supplies 

 of clothing, and increased intercommunication has so aided in its 

 distribution, that the protection and comfort of mankind have been 

 immeasurably enhanced, while a better knowledge of the hygiene 

 of clothing has prolonged many a life. The single item of water- 

 proof garments and rubber shoes has saved so many lives that the 

 philanthropist ought to rejoice that just as the cry began to go up, 

 " The Brazilian forests are becoming exhausted," Stanley opened 

 up boundless stores of rubber in Africa. 



The next great and widely operating cause of lengthened life 

 has been the extensive application of drainage-works, undertaken 

 primarily to give a higher agricultural value to land, but incident- 

 ally causing an abatement in fever and ague and all other types 

 of malarial disease, and also greatly lessening the cases of con- 

 sumption as damp soil is now recognized as the great predispos- 

 ing cause of lung diseases. In Birmingham, England, where the 

 drainage was good, the deaths were one in forty, in spite of many 

 insalubrious manufactories; while in Liverpool, where an un- 

 drained soil counteracted many sanitary advantages, they were 

 one in thirty-one. By the drainage of the Bay Ridge district of 

 Long Island, under an intelligent and judicious commission, not 

 only were malarious swamps changed into fertile corn-fields, but 

 the druggists testified that they sold one quarter only of the 

 quinine used before, and the resident physicians that there was 

 a cessation of chills and fever and all types of intermittent and 

 remittent fever. It should be noted, in passing, that all the land- 

 owners joined ; one obstinate obstructionist can nullify the good 

 intentions of a multitude of right-minded men. 



We now begin to come upon the widely operating reforms 

 consequent on the investigations and recommendations of sanita- 

 rians ; the first and greatest of which is the supply to multitudes 

 of communities of pure water ; sometimes tapping an uncontami- 

 nated supply by a pipe, and sometimes going below the element of 

 danger by an artesian well or other method of securing protected 

 water and thereby saving thousands from attacks of typhoid and 

 fatal diarrhceal diseases. It is beginning to be learned that con- 

 stantly drinking impure water creates a lowered vitality as much 

 as breathing a vitiated air, and that either one helps to supply 

 ready-made victims for any of the epidemic diseases. 



The next great sanitary reform has been a knowledge of the 

 true principles of ventilation. The need of pure air air that has 

 not previously been breathed by another person is by no means 

 as well understood as could be wished, but enlightenment is surely 

 making its way, and ancient evils are vanishing before it. A 



