Tlie influence of a meat diet on the kidneys. 205 



sponcliug to an early catarrlial nephritis. In one litter of three ani- 

 mals (p. Table IV) which were killed when three months old, the 

 kidneys present a perfectly normal appearance. 



V. In the series of four animals which were fed on ox-flesh for 

 nine months, the diet being- commenced when the animals w^ere about 

 three months old, the kidneys appear normal. 



The application of Mnir's haematoxylin-eosin stain ^) to the kid- 

 neys of the meat-fed subjects which appeared normal by ordinary 

 staining methods, shows a striking alteration in the granules of the 

 secreting cells. The changes may be briefly described as 



1. An irregular distribution of granules throughout the secreting 

 cells, the granules not being confined to the base of the cell as in 

 normal kidneys. Many granules may also be present in the lumen 

 (see Fig. 2). 



2. An alteration in the size and staining affinity of the granules, 

 the granules being much larger in size and taking a deeper stain. 

 The nuclei of the secreting cells are also more deeply stained (see I'ig. 2). 



In the kidneys which show catarrhal changes the granules are 

 very few in number or may be absent. 



Observations on nitrogen excretion. 

 By Andrew Hunter. 



To gain an idea of the conditions of some of the animals as 

 regards nitrogen metabolism the following experiments were made: 



Three adult rats, which for some time had been maintaining 

 nearly the same weight, were isolated in specially constructed cages. 

 These cages allowed of the collection of urine and faeces from day 

 to day. (To prevent the loss of urinary nitrogen as ammonia, a few 

 c. c. of dilute sulphuric acid were placed in each receptacle.) The 

 output of N in each case was then determined by submitting all the 

 faeces, and an aliquot part of the urine to the process of Kjeldahl. 

 The intake was calculated from the total amount of food consumed 

 (from a specially conducted analysis of each diet). 



') .Journal of Pathology Vol. XI, No. 3, p. 373. 



