POISONING WITH CARBON MONOXID. 59 



If carbon monoxid be inspired it gradually displaces, volume for 

 volume, the oxygen of the hemoglobin, and death finally results; 

 1000 cu. cm. of carbon monoxid will kill human beings if breathed 

 at once. Small amounts of carbon monoxid in the air (TTro~Trnnr) how- 

 ever, suffice to generate comparatively large amounts of carbon-monoxid 

 hemoglobin within a short time. As by means of long-continued 

 treatment of carbon-monoxid hemoglobin with other gases, particularly 

 oxygen, passing them through the carbon monoxid may be grad- 

 ually again separated from the hemoglobin, with the re-formation of 

 oxy hemoglobin, so in the body also the carbon monoxid is eliminated 

 through the respiratory process in the course of a few hours, a por- 

 tion of the carbon monoxid apparently being oxidized into carbon 

 dioxid. 



Poisoning with Carbon Monoxid. Carbon rnonoxid results from incomplete 

 combustion of carbon, as, for instance, through premature closure of stove-valves 

 and badly smoking lamps. It occurs in illuminating gas in a proportion of from 

 12 to 28 per cent. As carbon monoxid has 200 times as great an affinity for 

 hemoglobin as oxygen, more and more of the latter is displaced from the blood 

 by the breathing of air containing carbon monoxid, and life naturally can continue 

 only so long as sufficient oxygen is conveyed by the blood as is necessary to main- 

 tain the processes of oxidization essential to life. Death occurs amid peculiar 

 phenomena, even before all of the oxygen is expelled from the blood; under the 

 most unfavorable circumstances one-fifth of the oxygen will be retained in the 

 blood. 



Applied directly to nerve and muscle the gas has no influence whatever. 

 Acting through the blood, however, phenomena appear that are indicative 

 primarily of stimulation, but secondarily of paralysis of the nervous system. 

 Thus, there occur at first severe headache, great restlessness, excitement, 

 increased cardiac and respiratory activity, salivation, tremor, twitching, and 

 spasm. Later, mental confusion, exhaustion, drowsiness, and paralysis set in, and 

 even loss of consciousness, labored stertorous breathing, finally complete loss of 

 sensibility, cessation of breathing and of the heart-beat and death. The tem- 

 perature at the beginning exhibits an elevation of perhaps a few tenths of a degree 

 C.; then there follows a decline of about i C. and more. The pulse-beat at 

 first exhibits increased energy, while later the pulse becomes small and frequent. 



Garland-like constrictions of the vessels, followed later by marked dilatation, 

 with hyperemia of the viscera, accompanied by a fall in the blood-pressure, 

 indicate primary stimulation and secondary paralysis of the vasomotor center. 

 The change in temperature mentioned is to be referred to the same cause. This 

 would also explain the appearance of sugar in the urine sometimes observed 

 in dogs only after abundant feeding of proteid. After the intoxication has ter- 

 minated the excretion of urea is said to be increased, because the albuminates 

 exhibit a greater tendency to disintegration. In cases of poisoning the great 

 hyperemia of the viscera with fluid cherry-red blood and the dilatation of the 

 vessels are conspicuous. Further, there are friability and softening of the 

 brain, marked catarrh of the respiratory organs and granular degeneration of the 

 muscles. Liver, kidneys, and spleen appear hyperemic, large, flabby, in a state 

 partly of granular and partly of fatty degeneration. All of the muscles and 

 viscera exhibit an exquisite cherry-red color. The spots of postmortem lividity 

 are bright red. 



Poisoned persons if still living should be at once brought into the fresh air. 

 High degrees of intoxication demand transfusion. After recovery from the 

 poisoning, sometimes paralysis, rarely anesthesia, trophic disorders and derange- 

 ment of cerebral activity persist. If mixed with pure oxygen carbon nionoxid 

 acts less rapidly. 



OTHER HEMOGLOBIN-COMBINATIONS. 



Nitric-oxid hemoglobin is formed when nitric oxid enters into com- 

 bination with hemoglobin. 



As this gas in contact with oxygen is at once transformed into nitrous acid, 



