BIOLOGY. 281 



continued day after da} T , the experiments do not show. It is 

 quite obvious that alcohol is not necessary for him ; that is, that 

 every function was perfectly performed without alcohol, and that 

 even 1 ounce in 2-1 hours produced a decided effect on his 

 heart, which was not necessary for his health, and, perhaps, if 

 the effect continued, would eventually lead to alterations in cir- 

 culation, and to degeneration of tissues. It is not difficult to say 

 what would be excess for him ; but it is not easy to decide what 

 would be moderation ; it is only certain that it would be some- 

 thing under 2 fluid ounces of absolute alcohol in 24 hours. 

 It will be seen that the general result of our experiments 

 is to confirm the opinions held by physicians as to what must be 

 the indications of alcohol both in health and disease. The effects 

 on appetite and on circulation are the practical points to seize ; 

 and, if we are correct in our inferences, the commencement of 

 narcotism marks the point when both appetite and circulation 

 will begin to be damaged. As to the metamorphosis of nitro- 

 genous tissues or to animal heat, it seems improbable that alcohol 

 in quantities that can be properly used in diet has any effect ; it 

 appears unlikely (in the face of the chemical results) that it can 

 enable the bod} 7 to perform more work on less food, though by 

 quickening a failing heart it may enable work to be done which 

 otherwise could not be so. It may then act like the spur in the 

 side of a horse, eliciting force though not supplying it. Science 

 Review. 



EFFECTS OF COMPRESSED AIR ON THE MEN EMPLOYED IN THE 

 CAISSON OF THE EAST PIER OF THE ST. LOUIS BRIDGE. 



The first symptom manifesting itself, caused by the pressure of 

 the air, is painfulness in one or both ears. The eustachian tubes, 

 extending from the back of the mouth to the bony cavities over 

 which the drums of the ears are distended, are so minute as not 

 to allow the compressed air to pass rapidly through them to these 

 cavities, and when the pressure is increased rapidly the external 

 pressure on the drums causes pain. These tubes constitute a 

 provision of nature to relieve the ears of such barometric changes 

 as occur in the atmosphere in which we live. The act of swal- 

 lowing facilitates the passage of the air through them, and thus 

 equalizes the pressure on both sides of the drums, and prevents 

 the pain. 



The pressure may be admitted into the air-lock so rapidly that 

 this natural remedy "will not in all cases relieve it. By closing the 

 nostrils between the thumb and fingers, shutting the lips tightly, 

 and inflating the cheeks, the eustachian tubes are opened, and 

 the pressure on the inner and outer surfaces of the tympanum is 

 equalized, and the pain prevented. This method must be used 

 and repeated from time to time as the pressure is let on, if it be 

 increased rapidl}'. No inconvenience is felt b}~ the reaction when 

 the pressure is let off, as the compressed air within the drums has 

 a tendency to open the tubes, and thus facilitates its escape 



