HEAT EQUIVALENT OF NUTRIENTS OF FOOD. 



5^5 



fijL^iires given here aud later, that the small calorie denotes the amount 

 of heat required to raise 1 gm. of water of about 17° one degree in 

 temperature, and that the large calorie denotes the amount of heat 

 needed to raise 1 kg, of water of about 17° one degree. Where not 

 otherwise specified the large calorie is meant. 



Hiat of comhitnlion and clcineiitari/ composition of alhiiminoid siihsfaiiccs. 



SuLstaiico. 



riiiiit filirii) 



Sc I'll 111 ill 1)11 ineu 



Sviitciiiin 



H'ciiioul(,hin 



]\Iill< cnsciii I 



Milk ca.seiii 11 



Yi.lk (if e-g- 



Lr,i;illi)ill 



Aiti'liin 



Eirj;- albunu'ii 



Fiber nf meat (extracted 



witli water) 



Albiinieu (crystallized) 



]Meat. free from fat 



Do. 



Blond fibrin 



Haniack's albumen 



C'onulutin 



I'eptoue 



Heat 

 equiva- 

 lent per 



gram. 



Small 

 calories. 

 5.941.0 

 5, 917. 8 

 5, 907. 8 

 5, 885. 1 

 5, 867. 

 5,849.6 

 5, 840. 9 

 5, 793. 1 

 5,745.1 

 5, 735. 2 



5, 720. 5 

 5, 672. 

 5, 662. 6 

 5, 640. 9 

 5, 6:J7. 1 

 5, 553. 

 5, 479. 

 5, 298. 8 



Elementary composition. 



Carbon. 



^J^"- l^itrogen 



Per cent. 

 54. 39 



53. 93 

 53.64 



54. 73 

 54. 02 

 54.14 

 53. 50 

 53. 22 

 50.27 

 52. 95 



52.11 

 51.48 



Per cent. 

 6.92 

 7.65 

 7.44 

 6.06 

 7.33 

 6.85 

 7.31 

 7.17 

 7.90 

 7.50 



7. 10 

 6.76 



Per cent. 

 15.39 

 15.15 

 15.76 

 16. 5U 



15. 52 

 15.01 

 15.26 

 15.18 

 10.04 

 15.19 



10.44 

 18. 14 



16. 38 

 10.36 

 16. 72 

 14.51 

 17. 51 

 16.42 



Sulphur. 



Oxygen. 



Per ceiit. 



1.02 



1.18 



1.09 



.40 



. 75 



.78 



1.11 



.46 



1.09 



1.51 



1.03 

 .96 

 1.09 

 1.01 

 1.13 

 1.89 

 .79 

 1.24 



Chlorin. 



It is no more possible to speak of one value for the heat equivalent 

 of the albuminoids than it is to speak of a single uniform chemical 

 composition for the entire group. The beat equivalent is, however, 

 unquestionably proportioned to the amount of combustible elements. 

 It is often necessary to base calculations upon an average albuminoid, 

 and so also it is necessary to use an average heat equivalent, notwith- 

 standing the fact that the variations in the heat equivalent of the 

 different albuminoids may be quite considerable. This average value 

 is found to be 5,730,8 small calories per gram, and corresponds to the 

 average elementary composition. 



Per cent. 



Carbon 52.71 



Hydrogeu 7. 09 



Nitrogeu 16. 02 



Snlphm- 1.03 



Oxygen 23. 15 



100. 00 



Berthelot, who also investigated albuminoids, obtained 5,691 small 



calories as the heat equivalent. This number is so near ours that the 



mean between the two, 5,711 small calories, can be taken as the most 



probable value. Comparison of the results thus obtained with those 



13788— No, 7 2 



