F^CES. 375 



towards the close of the combustion, a precaution essentially ne- 

 cessary in the analysis of these matters, as the last trace of carbon 

 cannot, without this precaution, be completely burned. In 

 corroboration of this statement I may mention that the perfect 

 incineration of faeces at a red heat requires a considerable time. 

 The matter was prepared for analysis by first drying over the 

 water-bath, and then either in an oven at the temperature of 

 212 or some degrees above, or in the salt-water bath and by a 

 current of air desiccated by chloride of calcium. I was extremely 

 particular in respect to the drying, and, generally, in a second 

 analysis, employed matter which had been subjected to the 

 drying process for a much longer time than in the first, so that 

 the correctness of the proportion of hydrogen should be satis- 

 factorily tested. 



1st Analysis: 7'41 grs. gave of water 4-43 or of hydrogen 6-64g, of C0 2 12-55 

 or of C 46-18. 



2d Analysis : 7-24 grs. gave of water 4-44 or of hydrogen 6-81g, of C0 2 12-28 

 or of C 46-23g. 



Incineration : 50-13 grs. gave of ash 8-21, or 16'37g. 



Nitrogen not yet determined. 



Taking the mean, we have : 



C 46-2(K 



H 6-72 



N&O . . 30-71 



Ash 16-37 J 



L 100-00 



" These results are very nearly the same as those obtained 

 by Dr. Playfair, 1 at Giessen, His analysis gives C45-24, 

 H6-88, N&O 34-73, ash 13-15. These facts are worthy of 

 attention, as they seem to show that, under ordinary circum- 

 stances of health, the composition of the faeces is more uniform 

 than we might a priori have anticipated. The first analysis, 

 it will be borne in mind, was of the faeces of a man in this 

 country; the second, of a soldier at Giessen. 



" 2. A man undergoing the curious and rigorous discipline 

 of training for prize-fighting. This individual, it will not be 

 doubted, was in the possession of the most perfect health. He 

 had been in training for about a week. Age, 22; height, 5ft. 6in.; 

 weight, 8i stones. I request particular attention to the diet. He 

 breakfasted at 9 a.m., and took one pound of mutton weighed 

 before cooking. He dined at 1 p.m., took the same quantity of 



1 Liehig's Animal Chemistry, 2d edition, p. 285. 



