ZOOLOGY. 359 



hour, and who prevented him from taking any sleep, night or day. 

 He lived thus for nineteen days, without having slept for a single 

 minute. At the commencement of the eighth day his sufferings were 

 so cruel, that he begged, as a great favor, that they would kill him by 

 strangulation. 



PRESERVATION OF LIFE AFTER THE LOSS OF A PORTION OF THE 



SPINAL MARROW. 



M. BROWN-SEQUARD states, in a paper presented to the French 

 Academy on June 24, that he has found by experiment, that, if death 

 follows the destruction of portions of the spinal marrow, which are not 

 essentially necessary to respiration, it is caused by the hemorrhage 

 which follows, and not by the act of destruction. In proof of this he 

 details some experiments upon pigeons, which show that with them 

 life may continue for an indefinite time, certainly more than three 

 months, after the destruction of a portion of the spinal marrow equal 

 to half the length of this nervous centre. A comparison of two young 

 pigeons of the same age, fed upon the same food, one of them being 

 thus mutilated, shows that the weight and quality of the excrement is 

 the same, as are the increase of weight and the length of the limbs, 

 but the size of the leg, especially the thigh, is greater in the unharmed 

 bird. All these facts tend to show that circulation, respiration, di- 

 gestion, animal heat, urinary secretion, production of feathers, &c., 

 are the same in both birds. This is also the case with adult pigeons, 

 and, so far as has been examined, with many other birds. 



ON THE GEOGRAPHICAL DISTRIBUTION OF HEALTH AND DISEASE. 



SINCE the time of Hippocrates a belief has existed that the develop- 

 ment of the moral and physical faculties of man is dependent, not on 

 an original organization only, but also on the atmosphere by which he 

 is surrounded, and the nature of the soil on which he is reared ; and 

 modern researches in physical geography, combined with statistical 

 investigations in medical science, have confirmed this opinion. Swe- 

 den furnished the first tables of mortality ; since then England, France, 

 Prussia, and the United States have each contributed systematic sta- 

 tistical returns, and thus a vast mass of material has been accumulated, 

 from which valuable conclusions may be deduced, especially since it is 

 known that, during a similar series of years, the same diseases re- 

 appear with the most astonishing regularity, both as to periodicity 

 and extent, and with reference to moral as well as physical causes. 

 Endemic fever, including remittent and intermittent fever, prevails in 

 North America, the West India Islands, on the west coast of Africa, 

 in Syria, South Italy, the Ionian Islands, and in general the low, marshy 

 districts of warm countries. Yellow-fever is endemic in North Ameri- 

 ca and the West India Islands, between latitude 5 and 40 N., its 

 northern limit in Europe being the latitude of Gibraltar. Diseases 

 of the digestive organs are most prevalent in India, West and East 

 Africa, England, Guiana, &c. Diseases of the liver greatly predomi- 



