However skilled the housewife may be in the culinary art, there is one small item that often proves a stumbling block, and that is the proper method of opening and serving oysters. Many people have the bivalves sent direct from the fishmongers already opened, but this is not to be recommended, as the oyster once opened loses its delicate flavour rapidly, and once it is severed from the shell it soon dies.

Opening an oyster is simplicity itself when the knack is acquired.

Like all other things, there is a wrong and a right way, and the wrong way is the hardest of all, besides spoiling the delicate fish itself.

Oysters should be kept on a plate with the flat part of the shell upwards until required. If the rounded shell is uppermost the fish will open its shell and the delicate Juices will escape

Obtain an oyster knife of the pattern shown here, this being the most easy to man' ipulate. A block of wood shaped as in illustration should also be provided

Photos: Fleet Agency

Rest the oyster in the groove of the wooden block, inserting the blade of the knife in the shell at a point farthest away from the opener

Give the knife a dexterous twist, which will partly open the shell. Gently slide the point of the knife in, and with a side motion cut the adhesion to free the shell from the oyster. Press downwards on the shell without raising the knife, or it will cut into the flesh and spoil its appearance

The rounded shell can then be removed, the knife being used in the manner here shown to separate the lower adhesion of skin or muscle, when the oyster is ready to serve

Serve the oyster on the flat shell, garnished with parsley and pieces of lemon

By J. T. Brown, F.z.s., M.r.san.i.

Editor of " The Sanitary Record"

Characteristics of Milk - Constituents of Good Milk - The Use of a Lactometer - Precautions against Contamination of Milk - Sterilisation of Milk - Sour Milk - Curds and Whey

Milk, which partakes of the characteristics of both meat and vegetable foods, is one of the most important items in the domestic supply, because it enters into the diet of everybody, and is the mainstay in the feeding of the young, the old, and the sick.

Milk is unstable in character, very susceptible to contamination, and, being largely used in the raw state, requires to be carefully chosen and handled.

Good milk is opaque and yellowish white. It contains cream or fat (to an extent of between 2 to 4 per cent, of its weight), casein, sugar, and various salts (from 7 to 9 per cent, of its weight), a nd water. On being allowed to stand the cream rises to the surface, and the body of the milk becomes less opaque, and almost white in colour. But there always remains a certain amount of fat in the body of the fluid, the amount remaining being greatly lessened if water has been added. If allowed to stand and become sour the milk curdles, the casein, with most of the sugar, salts, and remaining fat, becoming solid, called curds, which partly floats on a thin greenish hued liquid, the whey. The latter contains very little fat, but some casein, and also sugar and salts.

An ordinary form of lactometer used to test the quality of milk. The richer the milk the more of the tube will appear above its surface

Nutriment in a pint of milk. 1. Protein. 2. Fat. 3. Sugar and Salts. 4. Water

To test the quality of milk use a lactometer, a glass tube with bulb marked with a scale. This will float in the milk. The richer it is the more of the tube will appear above the surface. The specific gravity of good milk will vary between 1.026 and 1.036. For general domestic purposes it should not fall below 1.028. Anything above 1.030 is a rich milk. Bearing in mind that the cream tends to separate and float to the top, before using the lactometer the milk should be stirred. The instruments are regulated for a temperature of 60 degrees Fahr., so it is necessary to correct the reading for any fall or rise in temperature, allowing one degree in specific gravity for every ten degrees of variation in temperature.

Milk should be kept in a cool place Warmth tends to hasten the separation of the cream, and to promote other chemical changes.

Being a natural, rich food, milk proves an excellent medium for the multiplication of bacteria, whether these be benign or the germs of specific diseases. Bacteria may be present in milk either naturally, being secreted with the fluid by diseased cows, or they may be introduced during the process of milking, either through milkers having dirty hands, the cows' bodies being unclean, or the atmosphere of the cowsheds being contaminated; or they may be introduced afterwards by careless handling and the use of dirty vessels. This last form of contamination may take place on the farm, in transit, at the retail dairy, or in the house of the consumer.

What has been said concerning the character and quality of milk shows the paramount necessity of securing supplies from a reliable source. The better-class dairymen, whether they are cowkeepers or not, see that the cattle are examined by qualified veterinary surgeons at frequent intervals, all suspected cows being removed and quarantined. The dairy staff have also to undergo medical inspection, persons with tuberculous taint, skin diseases, or betraying symptoms of possible contagious or infectious maladies being rejected. The cowsheds are also kept in hygienic conditions, and all vessels maintained in good repair, and scalded immediately after use.

For conveyance of the milk from the farm to the dairy, and from the dairy to the consumer, lock-up closed cans should be used, and these should be kept at a low temperature. It is also imperative that perfect cleanliness should prevail in the retail dairy, which should be reserved solely for the sale of dairy produce.

Precautions must also be taken in the house. Milk should be placed in glazed ware jugs, and stored in a cool, dark larder, where the air admitted from the outside is filtered. If milk is placed in a bowl, separation of cream takes place more quickly, owing to the exposure of a greater surface, and warmth hastens the process. The vessels should be scalded immediately after use. Avoid mixing milk from two or more deliveries.

Where delicate infants and invalids have to be considered, it is wise to have "nursery" or other rich milk delivered in sealed glass bottles. These can be placed in water in order to lower the temperature, and will then keep well for twenty-four hours or longer.

At one time it was recommended that all milk should be scalded, in order to lessen the danger of conveying disease by means of accidentally contaminated milk. But it is found that cooked milk does not agree with every constitution, and as it is not so easily absorbed by the digestive system it loses much of its dietetic value. Where, however, temperature or other conditions are against the chances of keeping milk fresh and uncontaminated, it is well to resort to Pasteurisation. This can be done by the dairyman or by the consumer, who may use a home-made outfit or one of the very simple and cheap appliances supplied by dealers. The milk, contained in bottles, is placed in a vessel with some contrivance to keep the bottles apart and steady. Water is added, and this is slowly brought up to boiling point, kept there for a few minutes, and then allowed to cool off. Pasteurised milk has been sterilised by this process, and if kept from the air will keep unaltered for a long time, but if exposed it is quite as susceptible to contamination as any other milk.

Section of home steriliser or Pasteurising appliance. The milk is contained in the bottles, which are placed in a vessel containing water. This is then brought slowly to boiling point and kept there for a few minutes, then allowed to cool

" Humanised "milk is pure milk intended for weak infants, and is standardised to represent very closely the natural food.

Milk that has been soured by means of the lactic acid bacillus does not agree with everybody, and should be rejected, though it may be safely used in the making of certain cakes and sweets which are subjected to high temperatures in cooking. The purposely soured milk, by the introduction of special cultures of bacilli (usually in the form of pellets), has been found very useful in certain cases, largely so with persons suffering from digestive troubles, but it should only be used under medical advice. Some regrettable accidents have occurred by the unwise use of milk soured on this principle. On the other hand, milk soured by means of rennet is an excellent food. This process gives us the curd in large lumps, which, broken up and eaten with sugar or salt, or with fruit, together with the greenish fluid whey,is very nourishing. Curds and whey may be prepared at home; but considerable skill is required in the use of fresh rennet, otherwise a bitter taste results. Rennet powder, sold in packets, may safely be substituted.

Cream is supplied in two forms - more or less fluid as it separates from the milk, with little or no aid from heat, and clotted (Devonshire) cream, which is prepared from milk allowed to stand for twelve hours and then placed on hot plates. Clotted cream keeps fairly well, but both kinds are often found to contain boracic acid, added as a preservative, and useful for this purpose, but injurious for digestion. The presence of the preservative can only be determined by analysis.