53 



Mammals' blood will not remain fluid when placed in a turtle's 

 heart. It does not seem living enough to preserve such highly- 

 organised blood in a fluid state. Blood drawn from the body 

 immediately after death coagulates firmly ; but if even a short 

 interval be permitted to elapse between death and the evacua- 

 tion of the blood no coagulation takes place. Carbonate of 

 ammonia occurs in the blood in cholera and fever. In yellow 

 fever the blood is as fluid as port wine, its corpuscles are dis- 

 solved, and it is strongly ammoniacal, the breath and excreta 

 being also charged with ammonia. The introduction of am- 

 monia, by artificial means, into the blood produces symptoms 

 resembling thcjse of typhus fever; namely — dry and dark 

 tongue, involuntary actions of the muscles, ending in convul- 

 sions, insensibility, great sensitiveness to sounds, obscure 

 vision, and death from coma. An excess of lactic acid in the 

 blood gives rise to the symptoms of rheumatism. This fact 

 has been demonstrated by experiments performed on the lower 

 animals, in which lactic acid was injected into their blood 

 vessels. Certain conditions of the body lead to fibrinous de- 

 posits within the blood vessels or in the heart, in consequence 

 of which the circulation may be suddenly arrested and death 

 ensue. Losses of blood, syncope, exhaustion, the action of 

 saline purgatives may produce such an effect. The truth 

 seems to be that the vital changes in the blood must go on 

 steadily, or its natural relations to the body cannot be main- 

 tained. In pneumonia a patient may be doing well when, 

 unexpectedly, he becomes restless, his features assume a 

 death-like expression, and he sinks rapidly and dies. A post- 

 mortem examination reveals the cause of death in the shape 

 of a clot in the right side of the heart. Other illustrations of 

 sudden death from a similar cause were given, and it was 

 pointed out that these mishaps arose from the proper balance 

 between the various constituents of the blood having been dis- 

 turbed, in some cases by a diminution in the quantity of the 

 corpuscles, in other cases from a draining away of the fluids 



