POPULAR MISCELLANY 



715 



in. turn draws from the air which has been 

 swallowed into the stomach. This organ be- 

 comes, then, in the diver, a reservoir of air. 

 It is evident from these observations that 

 if persons who have been trained to diving 

 can not remain under water more than four 

 minutes without exposing themselves to 

 great dangers, drowning mcn^who struggle 

 and inspire water can endure so long only 

 under extremely favorable circumstances. 

 The lesson is also taught that divers should 

 not inflate their lungs before plunging, but 

 should swallow air, which then passing from 

 the stomach to the lungs will support respi- 

 ration during a definite period of immersion. 



Exhanstion from Rowing - Contests. — 



Prof. W. P. Trowbridge has discussed, in a 

 paper read before the New York Academy 

 of Sciences, the question " whether the ex- 

 cessive training for long-distance boat-races 

 and the violent and long-continued muscu- 

 lar and nervous exertions incident to these 

 contests do not in reality result in unneces- 

 sary and hurtful exhaustion during a race, 

 and frequently in permanent injury to the 

 contestants." Prof. Trowbridge says: "The 

 boat-race involves the action of all the 

 muscles, those of the legs, arms, and shoul- 

 ders, as well as of the back ; and hence the 

 demands on the heart and lungs are the 

 greatest possible. The work which a rower 

 performs in each minute of a four-mile race 

 is easily calculated. The distance — 21,120 

 feet — is traversed in about twenty-one min- 

 utes. The speed is therefore practically 

 about 1,000 feet per minute. At this speed 

 the resistance to the boat in the water is 

 about 75 pounds. This resistance has been 

 determined experimentally as well as theo- 

 retically in England, the average result being 

 75 pounds. The work per minute for eight 

 men is therefore 75,000 foot-pounds, or 9,375 

 foot-pounds (4 2 foot- tons) for each man per 

 minute. At the rate of 350 foot-tons in ten 

 hours, the day-laborer performs work at the 

 rate of only six tenths of a foot-ton per 

 minute. The rower in the boat-race, there- 

 fore, performs work each minute equivalent 

 to the work of seven strong laborers, or at 

 the rate of nearly one third of a theoretical 

 horse-power each minute during the race. 

 The question now recurs : For how long 

 should these extraordinary efforts be sus- 



tained ? Four miles in distance and twenty- 

 one minutes in time mark extreme limits of 

 endurance according to all experience in 

 boat-racing ; and if races are practically de- 

 cided at the end of the third mile, or whether 

 they are so decided or not, the fourth mile is 

 a test not of skill and muscular strength, but 

 of the hearts and lungs of the crews. This 

 is rather serious business. Is it quite ra- 

 tional to make the ultimate endurance of 

 these vital organs in a dozen young men a 

 matter of sport and amusement ? It is hard- 

 ly to be expected that any boat-crew will in- 

 itiate a movement to reduce the length of 

 course from four miles to three ; to use 

 an appropriate expression, they ' would die 

 first.' Such a movement might be looked 

 upon as a confession of weakness ; but when 

 the suggestion comes from an outsider it is 

 made to all alike, and may at least be dis- 

 cussed with possible profit." 



Sanitation among the Negroes.— At a 

 Public Health Conference held in Louisville, 

 Ky., Bishop C. C. Penick read a paper in 

 which he says : " It was startling to the 

 North and the South alike, when the census of 

 1880 showed the tremendous increase among 

 the colored people, and the cry of alarm ran 

 through the land lest in the near future the 

 black should be the dominant race in this 

 country. The world did not recognize the 

 fact that the great source of Southern wealth 

 had consisted in making the negro prolific. 

 Everything that could be done was done to 

 eradicate all the diseases threatening to in- 

 terfere with this object. In short, a man's 

 negroes were a man's money, and you may 

 just rest assured that he looked after them." 

 When the race was released from bondage, 

 its momentum carried it up to those startling 

 figures of the 1880 census — figures which 

 Dr. Penick thinks we shall never see again, 

 for there is no longer an intelligent class 

 which has a direct pecuniary interest in the 

 health of the negroes ; the latter are leaving 

 the plantations for the less healthful sur- 

 roundings of the towns, and the enfeebling 

 vices of the town are spreading into the 

 country. In a pamphlet by Dr. G. B. Thorn- 

 ton, of Memphis, it is stated that, although 

 the white population of that city slightly 

 exceeds the black, yet in 1880 a fifth more 

 blacks than whites died, in 1881 a fourth 



