10 Nov., 1916.] Coiwparntive Food Vnliiex of JJnir// Produce. 669 



Carbohydrates, e.g., sugar, starch, cellulose (woody fibre), &c. 



These are converted into fat, and serve as fuel also. 

 Mineral matter or ash, e.g., phosphate of lime, iron, sulphur, salt, 



Szc. These form the skeleton, &c. 



Milk. 

 Milk is an article of diet whose sole function in nature is to serve 

 as food. 



The importance of the milk industry to the community is much 

 o-reater than its money value (as compared with other industries) would 

 imply. It is probable that the quality of the milk sup])ly bears a closer 

 relation to the public \iealth than does that of any other food. This is 

 partly because of the exceptional nutritive qualities of milk and the 

 prominent part Avhicli it plays in the diet of children and others to whom 

 the quality of the food is of special importance, and partly because the 

 fluidity and opacity of milk offer unusual opportunity for adulteration ; 

 atid the fact that bacteria readily grow and multiply in it makes it 

 especially im|)ortant that the milk be carefully guarded from contamina- 

 tion. Tt is, therefore, important that the milk industry be controlled 

 Avith all possible en re both as regards the nutritive and the sanitary 

 qualities of the ]iroduct. 



The qunlitative composition has been concisely stated by Richmond 

 MS follows: — 



" Tt is essentially an aqueous solution of milk-sugar, albumin, 

 and certain salts, holding in suspension globules of fat, 

 and in a state of semisolution. casein, together with 

 mineral matter. Small quantities of other substances are 

 also found." 

 The quantitative composition varies considerably Avitli the different 

 breeds of cattle, period of lactation, (Src. 



The average composition of cow's milk may be taken as follows: — 



060 calories itci- lb., whereas, after the usual lo.ss of fat in preparation 

 and cookintr the steak, onlv about 040 calories remain) ; but, from the 

 point of view of its digestibility, milk has a great advnntaerc over other 

 foods, largclv dne to the nature of its constituents. The cirbo-livdratc'* 

 riacto-ic or milk snirar) are alrea<1v in 'Solution. .-Mid '-eadv to be acted 

 n|Hin by the (li<'-c-^t ivc juice^; of ibc intent iin'«!. ami arc h^ss suseeptible 



