ASPHYXIA. 163 



diately after birth and at the age of a few days is sufficient to explain the 

 remarkable power of resisting asphyxia just after birth. 



Breathing in a Confined Space. An important question connected with 

 the physiology of asphyxia, is the effect on the system, of air vitiated by breath- 

 ing in a confined space. There are here several points which present them- 

 selves for consideration. The effect of respiration on the air is to take away a 

 certain proportion of oxygen and to add certain matters which are regarded 

 as deleterious. The emanation which has been generally regarded as hav- 

 ing the most decided influence upon the system is carbon dioxide ; but this 

 influence has been much over-estimated. In death from charcoal-fumes, 

 it is generally carbon monoxide which is the poisonous agent. Eegnault and 

 Reiset exposed dogs and rabbits for many hours to an atmosphere contain- 

 ing twenty-three parts per hundred of carbon dioxide artificially introduced, 

 and between thirty and forty parts of oxygen, without any ill effects. They 

 took care, however, to keep up a free supply of oxygen. 



These experiments are at variance with the result obtained by others, but 

 Regnault and Eeiset explained this difference by the supposition that the 

 gases in other observations were probably impure, containing a little chlorine 

 or carbon monoxide. This view is sustained by the experiments of Bernard 

 with carbon monoxide. In animals killed by this gas, the blood, both venous 

 and arterial, is of a bright-red color, which is due to the fixation of the gas 

 by the blood-corpuscles. In this way, the red corpuscles, which act normally 

 as respiratory agents, carrying oxygen to the tissues, are paralyzed, and the 

 animal dies from asphyxia. 



In breathing in a confined space, the distress and the fatal results are 

 produced^ in all probability, more by animal emanations and a deficiency of 

 oxygen than by the presence of carbon dioxide. When the latter gas is re- 

 moved as fast as it is produced, the effects of diminution in the proportion of 

 oxygen are soon very marked, and they progressively increase until death oc- 

 curs. The influence of emanations from the lungs and general surface is 

 undoubtedly very considerable ; and this fact, which almost all have experi- 

 enced more or less, has been fully illustrated in several instances of large 

 numbers of persons confined without proper change of air. Overcrowding 

 is one of the most prolific sources of disease among the poorer classes of 

 society ; and there are many forms of disease prevalent in large cities, that 

 are almost unknown in the rural districts and that can be alleviated only 'by 

 proper sanitary regulations, which, unfortunately, it is often difficult to en- 

 force. 



In crowded assemblages, the slight diminution of oxygen, the elevation 

 of temperature, increase in moisture, and particularly the presence of organic 

 emanations, combine to produce unpleasant sensations. The effects of this 

 carried to an extreme degree were exemplified in the confinement of the one 

 hundred and forty-six English prisoners, for eight hours only, in the " Black 

 Hole " of Calcutta, a chamber eighteen feet ( 5-486 metres ) square, with only 

 two small windows, and those obstructed by a veranda. Out of this number, 

 ninety-six died in six hours, and one hundred and twenty-three, at the end 



