At this point it is well to stress the fact that the mother's milk differs from that of the cow in some quite important particulars, and it is only by intelligently taking these differences into consideration that it is possible for us to prepare an artificial food that will be satisfactory. Principal among these differences are that cow's milk contains three times as much albuminous material as that of the human being, and that it is less rich by about half in milk-sugar; furthermore, the former is acid in reaction, while the latter is neutral, or faintly alkaline. It will be seen, then, that in order to prepare a modified cow's milk that will approximate that of the human being it is necessary to dilute it with water sufficiently to cause the albumin to approach in proportion that of mother's milk, and at the same time some alkali must be added to neutralize the excessive acidity. Modified milk prepared, however, from the whole cow's milk, would contain much less fat than is desirable, so that we must use in making it the upper third of the whole milk after it has been allowed to remain undisturbed for a number of hours; in other words, in making modified cow's milk we use a large proportion of the cream, with a less amount of the other constituents. The following table for calculating the proper proportion of milk to be used at the various periods of the infant's life may be recommended, as it gives quite as satisfactory results as those that are more elaborate; it also gives the frequency of feeding and the proper amounts that should be used. The table was devised by Dr. C. E. Boynton, of Atlanta, Georgia. Fat Quantity No. of percentage ounces at feedings in Intervals desired. feeding. 24 hours. by day. Premature 1.00 1/4 to 3/4 12-18 1 to 1-1/2 hrs. 1-4 day 1.00 1 to 1-1/2 6-10 2 to 4 " 5-7 " 1.50 1 to 2 10 2 " 2- week 2.00 2 to 2-1/2 10 2 " 3- " 2.50 2 to 2-1/2 10 2 " 4-8 " 3.00 2-1/2 to 4 9 2-1/2 " 2- month 3.00 3 to 5 8 2-1/2 " 4- " 3.50 3 to 5-1/2 7 3 " 5- " 3.50 4 to 6 7 3 " 6-10 month 4.00 5 to 8 6 3 " 11- month 4.00 6 to 9 5 4 " 12- " 4.00 7 to 9 5 4 " 13- " 4.00 7 to 10 5 4 "