862 



THE POPULAR SCIENCE MONTHLY, 



paralyzed after he reached home, so that he 

 considered his life iu danger. All the pre- 

 cautions suggested by experience and care- 

 ful observation were adopted for the protec- 

 tion of the men, and the cases of affection 

 were watched as they occurred. In all, 

 with six hundred men employed, one hun- 

 dred and nineteen cases important enough 

 to need medical treatment were reported at 

 both pieis, fourteen of which cases died 

 and two were crippled. Post-mortem ex- 

 aminations were held in the cases of eight. 

 Various theories have been proposed to ac- 

 count for the affection. Dr. Clark, of the 

 City Hospital at St. Louis, believed that the 

 congestion observed was caused by the forc- 

 ing of the blood in upon the interior organs 

 of the body in consequence of the increased 

 atmospheric pressure. Another physician 

 thought the men were poisoned by carbonic 

 acid which had been abnormally retained 

 within the system while in the air-chamber, 

 but which was set free as soon as the press- 

 ure was removed. Dr. Jaminet thou2;ht the 

 cases were due to physical exhaustion caused 

 by breathing an atmosphere of quadruple 

 strength, and supported his view by refer- 

 ence to the facts, all of which seemed to 

 agree with it. Professor Woodward does 

 not contradict his theory, but suggests in 

 addition that the vital energies of the men 

 taken sick were to a great extent paralyzed 

 by loss of heat, which was due 1. To the 

 expansion of the air in the lock while 

 coming out ; 2. To the expansion of the 

 free gases and vapors within the body when 

 relieved of the abnormal pressure ; 3. To 

 the liberation of the gases held in solution 

 by the liquids of the body ; 4. To the severe 

 physical effort of climbing the stairs. The 

 loss of heat taking place under diminution of 

 pressure from four atmospheres to one would, 

 if no heat were received from suri^ounding 

 objects, be enough to reduce the temper- 

 ature from 70 above to 106 below zero. 

 Taking into consideration the condition of 

 men who have been working hard, especially 

 if they have not been well clothed and fed, 

 it is not strange that they did, but rather 

 that more of them did not, succumb under 

 the combined effects of these four agencies. 

 Dr. Jaminet gives an implied confirmation 

 of these views by remarking in his pam- 

 phlet that " the paresis is but the result of 



reflex action caused by the spontaneous re- 

 frigeration of the whole system, but prin- 

 cipally of all the abdominal organs." It is 

 also worthy of remark that none of the 

 men were ever attacked on entering the 

 caisson, and none were ever sick while in 

 the air-chamber, no matter how long the 

 watch, but the attack always came on with- 

 in half an hour after leaving the air-lock, 

 or at the time. On the basis of this theory 

 Professor Woodward establishes a system 

 of rules for the management of men at work 

 in compressed air, embodying the principles 

 that only sound men should be employed, 

 that they should be guarded against exhaus- 

 tion, that they should not be exposed with 

 unnecessary suddenness to the change from 

 a compressed to the normal atmosphere ; 

 and that such a supply of heat should be 

 given every man that he could lose a large 

 amount and still have plenty left. 



The Study of Anthropology. M. P. 



Topinard classifies the anthropological sci- 

 ences in three divisions. The first division, 

 anthropology proper, is general, considering 

 the questions of man's place in nature, and 

 his origin, whether by special creation, or 

 by derivation from preexisting forms ; and 

 special, considering types, the classification 

 and origin, the laws of the formation, de- 

 velopment, death, and renewal of races. 

 To the second division he gives the name 

 of ethnography. It concerns the agglom- 

 erations of peoples, hordes, and tribes as 

 we meet them. Its interest is derived from 

 questions that are peculiar to it, and from 

 the fact that races do not exist in nature, 

 but are only abstractions, characterized by 

 types which we imagine to have existed 

 among ancestors. Nowhere can the real 

 existence of a race be discovered, but we 

 find two or three types, even among the 

 most savage and most isolated tribes. 

 Special ethnography relates to the descrip- 

 tion of each people ; general ethnography 

 to common questions of manners, customs, 

 aptitudes, industries, beliefs, institutions ; 

 to the past of the race, the environment, 

 circumstances in the evolution of human- 

 ity ; to sociology. The third division in- 

 cludes the complementary sciences, among 

 which archaeology, especially prehistoric 

 archaeology, holds the first rank. It fur- 



