ABSORPTION. 211 



of an animal to the inhalation of ether and his subsequent muscular 

 relaxation, general paralysis from fracture of the skull with cerebral 

 hemorrhage, and the action of curare, which also causes complete mus- 

 cular paralysis, are all known to be sometimes followed by sugar in the 

 urine. Schiff* has even found that, in various animals, compression 

 of the abdominal aorta for ten minutes, or tying the principal blood- 

 vessels of one limb, may induce, for the time being, a condition of dia- 

 betes. All these causes probably operate by accelerating the hepatic 

 circulation. 



III. Saccharine urine may also be produced by puncture of the 

 medulla oblongata in the floor of the fourth ventricle. This fact, first 

 discovered by Bernard, f is best shown in the rabbit by introducing 

 a narrow chisel-shaped instrument, with the cutting edge directly 

 transversely, through the back part of the skull and the cerebellum, 

 so that it shall pierce the posterior part of the medulla in the median 

 line, without passing completely through its substance. Glucose ap- 

 pears in the urine after one or two hours and continues to be present 

 for several days. The immediate effect of this operation, according 

 to Bernard, is to increase the activity of the abdominal circulation. 

 When successfully performed, the operation causes no serious disturb- 

 ance of the vital functions, and the animal recovers without permanent 

 injury. 



In all the above instances, the appearance of sugar in the urine is 

 temporary, depending on occasional disturbance of the circulation. 

 When, in man, this condition becomes permanent, it constitutes the 

 disease known as Diabetes mellitus. In this affection, which is gen- 

 erally progressive and fatal, the urine is increased in quantity, of high 

 specific gravity, and continuously charged with glucose, sometimes in 

 great abundance. Fluctuations are observable in its quantity at differ- 

 ent periods of digestion and under the use of different articles of food ; 

 saccharine and starchy substances causing its increase, and albuminous 

 matters its diminution. But it usually continues to appear in some 

 proportion, whatever regimen be adopted. 



* Journal de 1' Anatomic et de la Physiologie. Paris, 1866, No. iv., p. 365. 

 f Lepons de Physiologie Experimentale. Paris, 1855, p. 290. 



