TRANSACTIONS OF SECTION D. — DEPT. ANATOMY AND PHYSIOLOGY. 60S 



best. Having first tested the atmosphere of the ward in which I was about to 

 operate to ascertain that it did not contain free ammonia in any quantity, I placed 

 upon one of my hospital beds an indiarubber sheet, and over it another sheet of 

 pure linen, upon which the person to be experimented upon lay. Over his body 

 was placed a wooden cradle or canopy, covered outside with a thick felt, and lined 

 inside with linen, which coverings were to be carefully adjusted round his neck. To 

 raise the temperature with the canopy I used the lamp-furnace invented by the 

 late Surgeon-Major Wyatt, the flame from which fitted accurately through a hole 

 in the coverings guarded by a wooden ring. Considering the spirit-lamp of 

 Wyatt's furnace objectionable for many reasons, I substituted a Bunsen gas-burner. 

 To insure the regular renewal of the air within the canopy, and to prevent its 

 saturation, as well as to collect any free ammonia which might be evolved, I intro- 

 duced a tube leading from a Bunsen air-pump, which tube was connected with two 

 glass towers filled with large beads and charged with half an ounce of dilute 

 hydrochloric acid of known strength. Through another hole in the canopy I 

 introduced a Daniel's hygrometer, by which I was enabled to observe the tempera- 

 ture and calculate the degree of saturation of the atmosphere within. As the gas, 

 water, and re-agents employed contained some small portion of nitrogen, my first 

 task was to ascertain the constant error arising from this source. To effect this I 

 performed three blank experiments, omitting only the introduction of the person 

 to be experimented upon. The result was that I obtained a small quantity of 

 nitrogen nearly equal in each case and having a mean value of '063 grammes, 

 that being the total amount collected in one hour under the experimental con- 

 ditions. The water I used was Vartry water, and when I used it unfiltered 

 I employed the above number as a constant. As it would be necessary to 

 use filtered water in order to eliminate epithelium, I made three similar blank 

 experiments, using filtered Vartry water, and obtained another constant amount- 

 ing to -0408 grarnme of nitrogen, which I used in all experiments on filtered 

 water. The method employed for estimating the nitrogen was that to be described 

 hereafter. I commenced a series of experiments upon myself, with the assistance of 

 my clinical clerk, Mr. Clune. One of these I shall now describe. I first took a 

 sponge bath for the purpose of removing loose epithelial scab s, as well as minute 

 fibres from the under-clothing, which I always found adhering to the skin, and 

 having noted my pulse, respiration, bodily weight, and temperature, I entered under 

 the canopy. The coverings being carefully adjusted round my neck, the gas-furnace 

 was lighted, the air-pump and hygrometer adjusted, and the experiment continued 

 for an hour or an hour and a half, the time being carefully noted. Before leaving 

 the canopy the pulse, respiration, and bodily temperature were again noted, also the 

 mean temperature and. point of saturation of the atmosphere within the canopy. 

 On leaving the canopy I got into a bath containing 20 litres of Vartry water acidu- 

 lated with an ounce of the dilute hydrochloric acid of known strength. I took with 

 me into this bath the linen sheet upon which I had lain whilst under the canopy, 

 and with it I gently rubbed myself so as to remove any loose epithelial scales. On 

 leaving the bath I again weighed myself, and in twenty minutes after I again noted 

 my pulse, respiration, and bodily temperature. I caused the linen and india-rubber 

 sheets, as well as the towels containing the dilute hydrochloric acid, to be washed in 

 the water of the bath, and then brought a specimen of it to my laboratory for analysis. 

 The process of analysis of this water which I employed was briefly as follows : — I 

 carefully measured 100 c.c, and poured it into a partial-distillation flask, which 

 I altered to suit my purposes by shortening and bending the side tube upwards 

 towards the mouth. I now took a porcelain dish, in which I placed a small quantity 

 of pure sand carefully cleansed with hydrochloric acid, and subsequent washing 

 with distilled water, and moistened it with a drop of strong sulphuric acid. Hav- 

 ing placed the dish upon a water-bath, I inverted the flask into it, and, properly 

 suspending it, carefully evaporated the water as it gradually flowed into the dish ; 

 1 then removed the sand from the dish, and, mixing it with soda-lime, placed it in 

 a small combustion tube, and proceeded to estimate the quantity of nitrogen con- 

 tained in the 100 c.c. in the manner referred to in my former paper. Hence I 

 calculated the quantity contained in the 20 litres, and from this quantity I deducted 

 my constant, thus ascertaining the total quantity of nitrogen excreted by the skin 

 during the experiment. I have described an experiment in detail, as all the others 



