380 TEE POPULAR SCIENCE MONTHLY 



out as an invisible spray when we speak, sing, cough, sneeze. Sputum- 

 pots can not control this. The saliva of cases of phthisis may teem 

 with the bacilli. The tuberculin reaction tests carried out by Ham- 

 burger and Monti in Vienna show that 94 per cent, of all children 

 aged eleven to fourteen have been infected with tubercle. In most 

 the infection is a mere temporary indisposition. I believe that the 

 conditions of exhausting work, and amusement in confined and over- 

 heated atmospheres, together with ill-regulated feeding, determine 

 largely whether the infection, which almost none can escape, becomes 

 serious or not. Karl Pearson suggests that the death statistics afford 

 no proof of the utility of sanatoria or tuberculin dispensaries, for 

 during the very years in which such treatment has been in vogue, the 

 fall in the mortality from tuberculosis has become less relatively to 

 the fall in general mortality. He opines that the race is gradually 

 becoming immune to tubercle, and hence the declination in the mor- 

 tality curve is becoming flattened out — that nature is paramount as 

 the determinant of tuberculosis, not nurture. From a statistical in- 

 quiry into the incidence of tuberculosis in husband and wife and 

 parent and child Pearson concludes that exposure to infection as in 

 married couples is of little importance while inborn immunity or 

 diathesis is a chief determinant. Admitting the value of his critical 

 inquiries and the importance of diathesis, I would point out that in 

 the last few years the rush and excitement of modern city life has 

 increased, together with the confinement of workers to sedentary occu- 

 pations in artificially lit, warm, windless atmospheres. The same 

 conditions pertain to places of amusement, eating-houses, tube rail- 

 ways, etc. 



Central heating, gas-radiators and other contrivances are now dis- 

 placing the old open fire and chimney. This change greatly improves 

 the economical consumption of coal and the light and cleanliness of 

 the atmosphere. But in so far as it promotes monotonous, windless, 

 warm atmospheres, it is wholly against the health and vigor of the 

 nation. The open fire and wide chimney ensure ventilation, the in- 

 drawing of cold outside air, streaky air — restless currents at different 

 temperatures, which strike the sensory nerves in the skin and prevent 

 monotony and weariness of spirit. By the old open fires we were 

 heated with radiant heat. The air in the rooms was drawn in cool 

 and varied in temperature. The radiator and hot-air system give us 

 a deadly uniformly heated air — the very conditions we find most 

 unsupportable on a close summer's day. 



In Labrador and Newfoundland, Dr. "Wakefield tells me, the mor- 

 tality of the fisherfolk from tuberculosis is very heavy. It is generally 

 acknowledged to be four per 1,000 of the population per annum, 

 against 1.52 for England and Wales. Some of the Labrador doctors 



