218 THE UEINE. 



jected vessels of the coil are seen passing down the tube. From the 

 kidney of the deer. 



A difference of opinion prevails among anatomists as to the existence 

 of nucleated cells upon the Malpighian tuft or coil in the case of the higher 

 animals. This question is finally settled by Dr. Isaacs in the following 

 manner. An ethereal or watery-colored solution is injected into the ure- 

 ter, so as to distend the tubes, burst, and throw off the capsule. The 

 cells can then be seen upon the naked tuft or coil. Fig. 95 shows the 

 Malpighian body and uriniferous tube of the kidney of the black bear. 

 The artery had been first partially filled with injection, which had broken 

 the coil in pieces. The injection from the ureter ruptured the capsule, 

 which is seen in shreds. Nucleated cells are seen on the naked coil or tuft. 

 In the upper part of the figure, to the left, is a broken tuft, on the right of 

 which the ruptured capsule is perceived, and nucleated cells upon the 

 uncovered tuft. In the upper part of the figure, to the right, are the 

 fragments of a Malpighian tuft, with nucleated cells adhering to it. The 

 capsule had been torn off with a fine needle. All the above drawings 

 were made under the microscope. 



The urine of man is a clear, amber-yellow liquid, the average specific 

 The urine its g^^ty f which may be taken at 1.020, giving an acid re- 

 properties and action when first voided, but gradually becoming alkaline 

 and turbid. Its composition varies greatly with preceding 

 states of the system, and the nature and quantity of the food. It 

 amounts, in the course of a day, to from 20 to 50 ounces ; this, however, 

 depending on the quantity of water that has been taken, and on the ac- 

 tivity of the skin. Its solid ingredients vary from 20 to 70 parts in 1000 

 of the urine, the leading substances being urea, uric acid, lactic acid, ves- 

 ical mucus, epithelial debris, extractive, and salts. 



The urine of carnivorous differs from that of herbivorous animals, the 

 latter being turbid, and having an alkaline reaction ; that of the former 

 transparent, pale yellow, and acid. 



From Winter's experiments, it appears that for every thousand parts 

 of his weight a man discharges 25.9 parts of urine per diem, the max- 

 imum being 46.8, the minimum 14.0. A child, reduced to the same 

 standard, discharges 47.4 parts ; but a cat, fed on a flesh diet, 91.036. 

 The quantity of water thus removed depends, to a very great extent, on 

 the existing conditions of the system ; sometimes it is far less than would 

 answer to the amount that has been taken ; sometimes, on the contrary, 

 more. The solid material likewise exhibits very great fluctuations. 



Viewed as a group, the constituents of the urine are evidently the ox- 

 Ori in of the idized residues of the system, which, unable, from their not 

 other urine possessing the vaporous or gaseous form, to escape through 

 constituents. t j ie lungSj ^^ from t i }e ^ so i u ]bility in water, readily removed 



