EFFECTS OF GASES UPON THE BLOOD. 33 



color. The heart and lungs, and the bloodvessels supplying the intestines, were 

 engorged with black blood. The contractility of the muscles was completely 

 destroyed. 



The blood-corpuscles had undergone remarkable changes. They were shrivelled 

 and contorted, presenting innumerable shapes, anything but ellipsoidal. These 

 changes had taken place in the colored corpuscles in all the organs and tissues of 

 the body. The effects of the gas appeared to have been confined principally to 

 the exterior cell wall ; for, when they were treated with acetic acid, the nuclei 

 were brought out unchanged. The appearance of the colored corpuscles of a 

 Yellow-bellied Terrapin {Emys serrata), which had been kept in the carbonic acid 

 gas until its death, is represented in Fig. 5. 



Fig. 5. 



n€<S? c 







Blood-corpuscles of a Yellow-bellied Terrapin ( Emys serrata) which had been kept without fond or drink for several weeks, 

 and then placed in a tub of water and abundantly supplied with vegetable food for 30 or 40 days, and finally placed 

 in carbonic acid gas. 



The urine of all these Terrapins which were confined in carbonic acid gas, con- 

 tained grape sugar, which is not normally present in the excretions of the kidneys 

 of these animals. The offices of the blood-corpuscles being arrested, oxygen being 

 no longer conveyed into the system, grape sugar, the product of the action of the 

 liver, was not decomposed, and, accumulating in the blood, was eliminated by the 

 kidneys. 



When Terrapins were employed which had been starved for a great length of 

 time, the effect of carbonic acid gas upon the blood-corpuscles was not so evident, 

 on account of the concentration of the blood, and the sluggishness of the meta- 

 morphoses of their tissues, and the rapidity with which they fell victims to the 

 deleterious influences of this noxious gas. The effects of carbonic acid gas in alter- 

 ing the shape of the blood-corpuscles, were best seen in those Terrapins which had 

 been deprived of food and drink for several weeks, and then transferred to a tub 

 of water, and supplied with vegetable food. 



These effects are not produced upon the blood-cells of warm-blooded animals, 

 because they are so rapidly destroyed that the gas has not sufficient time to come 

 in contact, in large quantities, with the corpuscles and materially alter their struc- 

 ture. Cold-blooded animals live much longer in carbonic acid gas than warm- 

 5 



