272 Historical 



the peculiar influence upon our animals which we have observed in 

 men living in the same medium. We mention the effect of the rare- 

 faction of the air only in explaining the exaggerated distention 

 accompanying the numerous indigestions observed in our horses and 

 mules during the period of the siege. (Vol. Ill, p. 658.) 



In a special work, this same veterinary gives an account of a 

 series of very unusual symptoms, observed in the animals of the 

 expeditionary corps, in the crossing of Rio-Frio (3300 meters) . 



The animal passes from health to sickness without any preliminary 

 symptoms. The system is in a state of general tension, especially the 

 muscular system. The eyes are fixed, wild, brilliant, the face con- 

 tracted and the pupil dilated. The hind limbs and the whole hind- 

 quarters are the seat of spasmodic movements which are very 

 definite and easily detectable. The muscles of the stifle and the thigh 

 display partial quiverings. 



The mouth is filled with a white, foamy, and very abundant 

 saliva. The jaws are in a state of permanent contractility. There is 

 certainly an over-stimulation of the salivary glands. There is a mani- 

 fest desire to vomit. Frequent efforts with belching are easily 

 observed. The belly is not distended. There are a few slight colics 

 shown by a little uneasiness, but the animals do not lie down, aroused 

 instinctively by the desire to urinate or defecate. The genito-urinary 

 system is over-stimulated: there is a stubborn and painful erection 

 of the penis. The conjunctiva is in its natural state and shows no 

 very perceptible changes; it is moist and very slightly bloodshot. The 

 capillary blood system is not visibly changed. The heartbeats are 

 strong and tumultuous. One can see at a distance, without resorting 

 to auscultation, the hasty movements of diastole and systole, and can 

 count the throbs of this organ by looking from behind the knee; . . . 

 and yet, strangely enough, the state of the pulse is not appreciably 

 modified in its normal rhythm. 



The nostrils are dilated. The expired air is hot; respiration is 

 accelerated. The inspiration is shallow and the expiration deep. The 

 respiratory muscles are contracted and tense, and the flanks, drawn 

 upward, are separated by extremely pronounced projections. They 

 rise and fall up to twenty or twenty-five times per minute. 



There is rather general prostration of the nervous system than 

 evident over-stimulation of the brain. 



The symptoms which we have just listed continue for several 

 hours without increasing and then disappear evidently as the effect 

 of suitable measures. (Vol. IV, p. 258.) 



This strange series of symptoms apparently so dangerous, 

 which, however, never brought on any serious consequences, sug- 

 gested to M. Liguistin the idea of poisoning. Not all of his col- 

 leagues shared his opinion; "some explained the symptoms in ques- 

 tion by blaming chiefly the rarefaction of the air, slow asphyxia 



