Theories and Experiments 487 



paraplegia make me incline towards congestion in most cases; but 

 we have no proof that the gaseous tension did not sometimes cause 

 hemorrhages. 



Finally, in the case which we observed, in which paralysis began 

 more than 24 hours after the last dive, we can see only a condition 

 rather abnormal in divers, a passive congestion in which the effect of 

 the gases of the blood cannot be admitted. 



We have laid stress on severe congestions; all that we have said 

 can be applied to all diseases of divers, depending on varying degrees 

 of severity. The afflux of blood and perhaps the effect of the gases 

 which it contains takes place at different points, and the severity of 

 the attack depends upon the importance of the organ. The "fleas," 

 the muscular and arthritic pains, the hemoptyses or nasal hemorrhages, 

 the inflammations of the ear, and the visceral congestions are always 

 the result of the same cause: a reaction of the blood which is too 

 violent or badly directed, whether this reaction is due, as Foley thinks, 

 to the nervous influence which revives during the decompression, or 

 whether the action of the gases dissolved in the blood must be 

 involved. (P. 60.) 



From the practical and prophylactic point of view, like all the 

 authors who preceded him (except M. Foley), M. Gal draws this 

 conclusion that the decompression must be made slowly; he also 

 makes the recommendation that the greater the depth reached, the 

 shorter the time under water should be. Here, in fact, is the 

 schedule followed under his supervision: 



Up to 25 meters, even in uniform depths, the period of work under 

 water was an hour and a half. From 25 to 30 meters, the time was 

 reduced to one hour. From 30 to 35 meters, only a half-hour. Between 

 35 and 40 meters the divers stayed on the bottom only a quarter of an 

 hour. 



Our fishermen never went below 35 meters. The Greeks, who are 

 more daring, went to 54 meters, in 1867. 



At the same time that the length of the shift was decreasing, the 

 time spent in the decompression was increasing. A half-minute per 

 meter was the rule first established; but the fishermen were never 

 willing to submit to it. They ascended at about 4 meters per minute. 

 (P. 72.) 



iPars altera. Rome, 1681. 



2 hoc. cit. Collect, acad., foreign part, Vol. I, p. 46-61, 1755. 



3 Elementa physiologiae corporis hutnani, Vol. Ill, 1761. 



4 Extrait d'une lettre de M. A. an citoven Van Mons. Ann. de Chimie, Vol. XXXVII. 

 1801. 



5 Article Air in the Diet, des Sc. med. Vol. I, p. 218, 1S12. 



6 Tractatus physioo-medicus de atmosphera et acre atmospherico. Cologne, 1816. 



7 Recherches sur les causes du m&uvement du sang dans les vaisseaux capillaires. C. R. 

 Acad, des Sc, Vol. I, p. 554-560, 1835. These different experiments are reported in detail in the 

 memoir of this same author, included in Volume VII of the Memoires des savants etrangers. 



8 Etudes de physique animate. Paris, 1843. 



9 Note sur la carbonometrie pulmonaire dans I'air comprime. Gas. med. de Lyon, 1849, p. 

 168. 



10 This method is explained in a previous work by the same authors, entitled: Recherches 

 sur les quantites d'acide carbonique exhale per le povmon a I'etat de sante et de maladie. Ibid., 

 p. 39-50. 



11 hoc. cit. Essai, etc.; 1850. 



12 hoc. cit. See above, Title II, Chapter I, section 2. , 



