Theories and Experiments 465 



everything so that in this little chamber the air pressure may reach 

 2.5 atmospheres, at the most. 



And certainly you will possess a piece of furniture which will 

 allow you to relieve many asthmatic old men, to save many children 

 attacked by croup, and also to cure many adults afflicted with conges- 

 tional, toxicohemic diseases. (P. 135.) 



Without discussing the value of these hopes, we must call the 

 attention of the "realizers," as M. Foley calls them, to the fact that 

 the construction of the apparatuses is considerably more compli- 

 cated and more expensive than he seems to think. 



M. Caffe 22 was commissioned by the Societe Medicale d'fimula- 

 tion to investigate the work of M. Foley. He took advantage of 

 the opportunity to study the effect of compressed air in his turn. 



He first accepts the ideas of Dr. Frangois about the mechanical 

 effect of compressed air and about the "amalgamating" of the air 

 and the tissues; he summarizes them in the following words: 



M. Frangois attributes the muscular and arthritic pains to the 

 penetration into the tissues of compressed air, which becomes a cause 

 of irritation, designated as "caisson pain"; abscesses sometimes follow. 

 An experiment seems to confirm the opinion of M. Frangois; at the 

 time when the caissons were being sunk, when the oak timbers, which 

 had been subjected to the compressed air, were removed from within 

 the caissons, these beams, when plunged into water, gave off consider- 

 able quantities of air bubbles. 



The danger of cerebral congestions is likewise referred to the 

 exit from the lock-chamber; when the blood has been freed from the 

 pressure of the compressed air, it tends to establish an equilibrium 

 with the outer air; it therefore is urged towards the nervous centers, 

 brain, and spinal cord; even the urinary bladder loses its contractility. 

 (Page 2.) 



Then after reporting the observations and theories of M. Foley, 

 he declares himself a very ardent partisan of his "sedan chair," and 

 cries out enthusiastically: 



We shall then possess an ingenious apparatus which will become a 

 valuable therapeutic resource for the solace and prolongation of the 

 life of many catarrhal and asthmatic old men, and for relieving pains 

 so hard to witness and to endure in adults afflicted with angina 

 pectoris, who turn blue and suffocate while seeking the air which 

 eludes them. 



Without any effort of the imagination, but proceeding with the 

 logic of data and reasoning, we can picture the hope of saving from 

 imminent death the victims of the last stages of croup. The compressed 

 air will depress and flatten the false membranes, and will restore 

 free passage of the air in the respiratory tracts. Cerebral congestions 

 and predispositions to apoplexy will be warded off as long as the nerve 

 influx controls the circulation; perhaps* we may even hope that typhus, 



