When the whey is the product of soured milk, 0.33 or more of lactic acid is to be added to this analysis, and the same amount deducted from the sugar of milk. Essence of pepsin will curd lukewarm milk, not warmer than can be agreeably borne by the mouth; a temperature higher than one hundred and fifteen degrees Fahrenheit destroys the curdling principle of the pepsin. The quantity of essence of pepsin to be used to the pint of milk depends on the strength of the preparation; usually a teaspoonful or two is added and stirred just enough to mix; let it stand till firmly curded, then beat up with a fork until the curd is finely divided; now strain and the whey is ready for use; it should be sweetened a little; sugar of milk, if pure, would be the best, otherwise white cane sugar may be used. A newborn babe will require a tablespoonful to begin with, every two hours, always slightly warmed. It is particularly essential to keep everything clean, especially the tube and nipple; these are to be brushed and cleaned after each meal, and then laid on a clean dry plate for future use; the nursing bottle too must be rinsed and drained. The prevalent custom of keeping the tube, nipple and bottle in water after they are washed is a bad one, for to have them sweet and pure they should be allowed to dry out between times. Condensed milk is often a valuable substitute for fresh cow’s milk; its utility, is probably due to the employment of heat in its manufacture, which destroys the germs or spores that find their way into all milk, and to the scalding of the casein which modifies its physical character so that it no longer curds into large lumps when in the stomach, but into smaller flakes. There are different brands in the market, and even the best of them may be too old and shop worn; they then become thick and dark in which condition they are no longer fit for infants’ food. The Eagle and Anglo-Swiss are among the best varieties; others contain too much sugar, while some are adulterated with starch or flour. A heaping teaspoonful of condensed milk to a teacupful of warm water, previously boiled, is the average strength, although better results are obtained when a thin gruel of corn starch or arrowroot is employed instead of plain water; when the child grows older cracked or rolled oats or graham flour may be substituted for the arrowroot. The gruel is prepared in the following manner: take half a teacupful of oatmeal or graham flour, saturate first with cold water, then stir slowly into three pints of boiling water; add a pinch of salt and boil over a slow fire for three-quarters of an hour, stirring constantly so that it will not scorch on the bottom; then strain, and if it has boiled down to less than a quart of gruel, add a sufficient quantity of boiling water through the strainer to make it measure a quart.