1. Skimming.

2. Boiling.

3. Dilution with water.

4. Dilution with alkaline and aerated waters.

5. Dilution with amylaceous foods.

6. Addition of alkalies, acid and other substances.

1. Skimmed Milk

Skimmed Milk is the residue after removal of the cream. It contains water, 90.63 per cent; proteid, 3.06 per cent; fat, 0.79 per cent; sugar, 4.77 per cent, and a residue of salts. It thus retains almost 10 per cent of solids.

Skimmed milk is well digested by those patients whose stomachs do not tolerate fat in any form, but it will not long support life, and attempts which have been made to cure certain diseases by a skimmed-milk diet have signally failed. Donkin advocated its use to the extent of six to eight pints daily.

It may be employed temporarily in the milk cure for Bright's disease, dropsies, and in the treatment of neurotic hysterical cases.

Yeo advises gouty subjects to drink ten minutes before each meal a breakfastcupful (eight ounces) of hot skimmed milk and water with the addition of a small saltspoonful each of potassium bicarbonate and salt. This is a good means of prescribing an alkali, but there is no special advantage in the skimmed milk.

2. Boiling

Boiled milk exhibits a thin scum of albumin upon the surface which entangles some of the fat globules, and which is quickly replaced by another after removal. This scum should not be served to invalids. There is much discussion as to whether infants should ever be given raw cow's milk, or only that which has been previously boiled, and authorities are divided upon the matter. Certainly in most cases raw milk, if pure, provokes no harm. Boiling the milk arrests the development of germs and fungi with which it may have become contaminated, and may thus prevent the spread of some diseases, and it retards the process of "souring" and coagulation. Boiling expels about 3 per cent of gases - carbon, nitrogen, and oxygen (Hoppe) - and the loss of oxygen diminishes the formation of lactic acid and consequent souring. It alters the taste of the milk somewhat, and makes it "flat." The flatness is removed by agitating the milk with air by pouring it back and forth into two cups held a little distance apart; or it may be removed by the addition of any aerated water.

As a rule, boiled milk is preferred hot, but some persons enjoy it cold.

It is a prevalent idea that milk is in general more digestible if boiled than if raw, but the results of experiment do not wholly confirm this view. Crolas has demonstrated that boiling has no influence upon either the lactose or casein, but it slightly increases the free soluble phosphates, which he regards as an advantage.

Radnitz found by experiment that young animals absorb 9.4 per cent of albuminoids from fresh milk, but only 5.7 per cent from boiled milk, hence a larger quantity of the latter must be drunk to obtain the same nourishment which is derived from raw milk.

According to Vasilieff, the envelopes of the oil globules are altered by heat, and he claims that 50 per cent less fat is absorbed. This seems too high an estimate in view of clinical observation.

Occasionally patients are made bilious and constipated by the use of boiled milk who digest it better raw, but the converse is also true: it is a matter of idiosyncrasy. It has decided advantage in diar-rhceal diseases, probably through the absence of germs and gases. In some cases it may be combined with thin chocolate or cocoa.

"Scalded milk" is heated to about 1500 F., or practically "Pasteurised," by pouring on boiling water. Thus treated, milk remains fresh a little longer than when raw.