STATICS 119 



A kilo-calorie is 1000 small calories, i.e. the amount of heat 

 required to raise the temperature of 1000 grams of water 

 iC. 



In this country the metric system is used only for scientific 

 purposes * the standard of mass employed in commerce and 

 agriculture is one pound. This standard is adhered to 

 throughout this book, and it is convenient, therefore, to define 

 the unit of heat, for present purposes, in terms of the same 

 unit of mass. The pound-unit is the amount of heat required 

 to raise the temperature of i Ib. of water i C. The "kilo-, 

 pound-unit," which may be briefly designated by the symbol 

 " kt.," is the amount of heat required to raise the temperature, 

 of 1000 Ibs. of water i C. This kilo-pound-unit gives con- 

 veniently small numbers which are easily compared with 

 those of the metric system. 1 



HEAT OF COMBUSTION (PER LB.) OF PROTEINS, AMIDES, FAT, AND 

 CARBOHYDRATES FROM SEVERAL SOURCES. 



Proteins. 

 Kt. Kt. 



Crystallised albumin . . 5*672 



Egg albumin .... 5735 



Serum albumin . . . . 5*918 



Haemoglobin .... 5*885 



Muscle 5*663 



Milk casein 5*86; 



Wool 5-564 



Peptone S' 2 99 



Plant fibrin 5*9*8 



Legumin 5' 793 



Mean 573 1 



Amides. 

 Kt. Kt. 



Urea 2*542 



Uric acid 2*750 



Hippuric acid .... 5*668 



Creatin ...... 4*275 



Glycol 3*129 



Sarcosine 4'56 



Alanine 4'3SS 



Leucine 6-525 



Tyrosine 5'9 I 5 



Asparagine 3'5 J 4 



Mean 4*3*8 



1 In. the units of the metric system, the heat of combustion of starch 

 is 4*1825 kilo-calories per gram ; in terms of the unit defined above, it 

 is 4*1825 kilo-pound-units per pound. In other words, the heat developed 

 by burning I gram of starch will raise the temperature of 1000 grams of 

 water 4-1825 C. ; and the heat developed by burning I Ib. of starch will 

 raise the temperature of 1000 Ibs. of water 4-1825 C. 



