3 8 THE POPULAR SCIENCE MONTHLY. 



foul burrows, while their neighbors preferred a manlier way of secur- 

 ing themselves against enemies and wild beasts, and saved themselves 

 from the glow of the midsummer sun by cultivating shade-trees. 

 "Herodotus speaks of persecutions," the doctor remarks, " but this 

 fixed custom of theirs may perhaps be attributed to vicious habit, 

 strengthened by hereditary transmission, quite as much as to neces- 

 sity, for men can become fond of vitiated air, as they contract a pas- 

 sion for fermented drink or decayed food." 



It seems really so, if we reflect on the hereditary perversity of 

 millions of Europeans and North American citizens, who in the midst 

 of social security, and without the excuse of the persecuted Nubians, 

 insist on secluding themselves and their children in the foul atmos- 

 phere of tenement-houses, factories, and workshops, which might just 

 as cheaply be supplied with pure as with warm air. 



The air we breathe, which a great English physician calls gaseous 

 food, may become impure to the degree of being indigestible to our 

 lungs and utterly unfit for the performance of functions which are 

 quite as important as those of our solid and fluid victuals. Dull 

 headaches, nausea, loss of appetite and of the sense of smell, and the 

 sadness produced by the unsatisfied hunger after oxygen, are only 

 incidental and secondary evils ; the great principal curse of the trog- 

 lodyte-habit is its influence on the respiratory organs. In 1853, when 

 Hanover and other parts of Northern Germany were visited by a very 

 malignant kind of small-pox, the great anatomist Langenbeck tried 

 to discover " the peculiarity of organic structure which disposes one 

 man to catch the disease while his neighbor escapes .... I have cut 

 up more human bodies than the Old Man of the Mountain with all his 

 accomplices," he writes from Gottingen in his semi-annual report, 

 " and, speaking only of my primary object, I must confess that I am 

 no wiser than before. But, though the mystery of small-pox has 

 eluded my search, my labors have not been in vain ; they have re- 

 vealed to me something else the origin of consumption. I am sure 

 now of what I suspected long ago, viz., that pulmonary diseases have 

 very little to do with intemperance or with erotic excesses, and much 

 less with cold weather, but are nearly exclusively (if we except tuber- 

 culous tendencies inherited from both parents, I say quite exclusively) 

 produced by the breathing of foul air. The lungs of all persons, 

 minors included, who had worked for some years in close workshops 

 and dusty factories, showed the germs of the fatal disease, while con- 

 firmed inebriates, who had passed their days in open air, had pre- 

 served their respiratory organs intact, whatever inroads their ex- 

 cesses had made on the rest of their system. If I should go into 

 practice and undertake the cure of a consumptive, I should begin by 

 driving him out into the Deister (a densely-wooded mountain-range of 

 Hanover), and prevent him from entering a house for a year or two." 



The ablest pathologists of the present time incline to the same 



