286 



ANIMAL FOOD. 



ingredients which would prevent its keeping sweet and fresh. Salt 

 is added to preserve it. If sirup be added instead of salt, or 

 sugar with which is mixed a little salt, butter is said to keep better. 

 The exclusion of air also preserves it, and simply covering it with 

 water renewed every day will keep it fresh for a week. But a better 

 plan is that of M. >reon, w r ho adds water slightly acidulated \vith 

 acetic or tartaric acid and places the whole in a closely fitting vessel. 



When pure and fresh, butter is more easily assimilated by deli- 

 cate stomachs than most other fats. It is also the form of sepa- 

 rate fat which is less frequently disliked by consumptive people and 

 invalids generally, but it should not be too bountifully supplied. 

 Butter that has become stale or rancid or been exposed to heat (as 

 for buttered toast), is very likely to disagree with dyspeptics and other 

 invalids and cause diarrhea. Indeed, as a rule, all decomposing fats 

 disagree with the stomach. There are ready means or detection 

 through the senses of sight, taste and smell, when butter is adul- 

 terated. Pure butter should be of a uniform rich yellow appearance ; 

 when a streaky look is imparted by quickly passing over it a clean 

 knife the presence of adulterants is always to be suspected. When 

 melted it should yield a clear-looking oil, with but slight deposit of 

 water or other substances. When placed on the tongue it melts 

 quickly and leaves the tongue perfectly smooth; while, on the con- 

 trary, there will be a sense of roughness, a granular taste and the 

 peculiar flavor of the adulterant as the results of this test when 

 butter is adulterated. None of these tests are of value in oleo- 

 margarine adulteration. The odor of butter is very persistent and 

 therefore does not so well mark its purity or the reverse. 



CHEESE is the nitrogenous portion (caseine) of milk, with a 

 proportion of fatty matter, obtained by coagulation into curd by 

 means of rennet or vinegar. The curd is subjected to pressure in a 

 mould, of the future form of the cheese, in order to remove the 

 whey. When sufficient consistence has been secured the cheese is 

 exposed in a cool, airy situation to dry and ripen. During this 

 process both caseine and butter undergo change, volatile, fatty acids 

 are produced, flavor is developed, and in some cases fungi are 

 formed. The rich and soft quality of the cheese depends on the 

 amount of fatty matter in the milk from which the cheese is made; 

 the richer cheeses are formed by the addition of an extra quantity 

 of cream; the poorer cheeses are made from skim-milk. Poor, 

 close cheeses keep the best. 



As cheese is rich in nitrogenous matter, it stands very high in 

 the scale of nutritious food ; one pound being equivalent to three 

 and a half pounds of lean beef. Taken with breaoT or other veget- 

 able diet, it is very nutritive to persons of active habits. As a relish 

 or condiment it stimulates digestion. But on the whole it is not 

 very digestible and therefore not suitable for persons of sedentary 

 habits or invalids, especially at bedtime. The close, poor cheeses 

 are less easily assimilated than the soft, brittle and strongly flavored, 



