206 THE FLUIDS. 



growth and development are rapid, it cannot be so for the aged. 

 Seizures simulating apoplexy are sometimes produced by milk in 

 aged persons not accustomed to its use. 



Woman's milk usually becomes suddenly deficient in caseine at 

 the end of a year after parturition. This may be accepted as an 

 indication that lactation should not, as a general rule, be prolonged 

 beyond this period. Up to this time it becomes more and more 

 nutritious, in proportion to the increased size and strength of the 

 infant. 



It frequently becomes necessary to substitute the milk of one of 

 the lower animals for that of woman, and the following facts are of 

 interest on this subject: 



1. Cow's milk contains a small amount more of solid constituents 

 than woman's milk, in the proportion (average) of 140 to 120 in 

 1,000 of milk. It contains more caseine (41.6 : 34.3), more fat 

 (45 : 25.3), and far more salts (7 : 2.3). On the other hand, it con- 

 tains less sugar (38.5 : 48.2). 



Consequently, if from 1,000 parts of cow's milk nearly one-half 

 (J) of the cream is first removed, and then 186 parts of water and 

 10 parts of sugar be added, the result will, in composition, very 

 nearly resemble woman's milk, except that the salts will still be too 

 abundant. The following formula will, therefore, answer, for prac- 

 tical purposes, as nourishment for an infant : 



R. Cow's milk . . 16 ounces (1 pint). 



(Remove one-half the cream.) 



Water ; ' . . 3 ounces (6 tablespoonfuls). 

 Sugar . . / ~l Bounce (a large teaspoonful). 



2. Goafs milk is sometimes substituted for that of woman. It 

 contains 132 to 145 of solid constituents, of which 40.2 to 60.3 are 

 caseine, 33.2 to 42.5 are fat, and from 40 to 53 are sugar, in 1,000 

 parts. 



3. The milk of the ass has less (only 91.6 to 95.3) of solid con- 

 stituents, there being only 16 to 19 of caseine, from 12.1 to 12.9 

 of butter, and 62.9 to 68 of sugar. It is the richest of all in sugar, 

 but poor in caseine and butter. 



4. Mare's milk contains 162 in 1,000 of solid residue, but little 

 caseine (17), a large amount of fat (69.5), and the most sugar of all 

 (87.5). 



5. Sheep's milk contains 143.8 of solid constituents, 40.2 being 

 caseine, 42 fat, 50 sugar, and 6.8 salts. 



A formula may be easily deduced from the preceding data, if it 

 be desirable to sustain the human infant on the milk of either of 

 the four animals last mentioned. 





