where it had "turned" and thus formed a nidus for loppered particles which acted upon the new milk and changed it in so short a time?"

The danger that the ferment may find a permanent lodgment in wooden vessels, together with the great amount of labor which their use involves, should cause their banishment from the cheese dairy in all cases where metallic ones can be substituted to advantage. If wooden utensils must be used, great caution should be had not to employ any which have been recently painted. On this point Mr. Willard remarks; "Sometimes when the dairyman has been using newly painted pails and tubs he will find black specks and spots on the rind of many of his cheeses, and should he cut them, the same peculiarity is presented throughout the cheese. This is poison cheese, more or less dangerous to the consumer, and justly feared and avoided in market; for although much of it may possibly be eaten in small quantities without producing any serious sickness, yet the chances are that some of the cheese is very poisonous. Now the dairyman often, and perhaps generally, is ignorant of the cause and innocent of any intent to poison, and he learns with amazement that his cheese has been thrown out of market, or sent back to him, or that some family has been poisoned by eating it; but such is the fact, and the result has been brought about by carelessly using newly painted utensils. The milk and whey have extracted poison from the lead and deposited it in the cheese. The fact has been well substantiated from numerous cases where the matter has been fully traced out. When utensils are to be newly painted it should be done at a time when they will not be needed for three months; and before painting they should have been thoroughly scrubbed with strong lye, in order that all the old flaky paint be removed and a good clean surface presented for the new paint. After the new paint has become thoroughly dried and hard the tubs and pails should be frequently soaked with water and whey until there is no smell or taste from the new paint."

The cleanliness referred to should include not only the utensils but every part of the premises. Milk absorbs odors of any kind with such facility that much caution needs to be exercised lest it suffer injury by exposure to offensive effluvia.

Let milk be ever so rich, it may be spoiled before, as well as after rennet is added.

Having secured cleanliness in all the appurtenances belonging

to the dairy, having before us pure milk in clean vessels, the next points are, the degree of acidity, and the temperature at which it should be set, i. e. the rennet added to it.

When milk is drawn from the cow it is sometimes alkaline, sometimes neutral, and sometimes acid, oftentimes in summer; never acid so as to taste sour, but sufficiently so to exhibit an acid reaction to a delicate test.* As soon as exposed to the air there commences a spontaneous conversion of the sugar (of which milk usually contains from four to five per cent.) into lactic acid. The chemical composition of these two substances, as determined by analysis, is the same; yet they are very different substances, to our senses of sight and taste, and the difference is supposed to be due to a transposition of the elementary atoms of the sugar.

Some hold that cheese is best made from new milk. It is true that when too much changed only a hard, sour cheese can be made from it. It is also true that those cheeses which bear the highest reputation and command the highest prices, both in this country and in Europe, are not made wholly from new milk, but from evening's and morning's milk mixed. From all the evidence presented, I entertain no doubt that the latter is the better practice; or in other words, that it is desirable that the conversion of milk sugar into lactic acid should have made some progress. The precise degree of progress which is best is not definitely known, nor have we at present any easy method of measuring it with precision, but practically it is found that if milk be kept for twelve hours at a temperature of about 65°, and the morning's milk be then added, and the whole properly warmed, the best results follow, and the due separation of the whey is more easily effected.

In the Cheddar method, which from its advantages both in the saving of labor and superiority of product, is rapidly displacing older methods of cheese-making in England, sour whey is usually added, but this is unnecessary in this country, at least in most cases during the summer months, because of the higher temperature which here prevails, which insures more rapid progress towards acidity, and more caution is required that it do not progress too far than not far enough. Mr. McAdam, a skillful practitioner

* Litmus paper is used for this purpose. It is colored blue by a vegetable infusion. A very slight degree of free acid in any liquid is detected by the reddening of the paper, and when thus reddened, a very little alkali suffices to restore the blue.

and teacher of this method, says, "When the temperature of the cold milk is 65° or upwards, no sour whey ought to be used, the acid then being present in a sufficient degree without it. When the temperature is higher, every operation of the process needs to be accelerated, until the curd is taken out and salted; for when too much acid is present, it affects the curd so as to render the cheese hard and give it a sour taste."

The temperature of the milk when the rennet is added is next to be attended to, and is a point of great importance. It has been found by experiment that milk coagulates soonest when at a temperature of about 115°,* but when curdled at so high a temperature the product is much injured. The proper temperature, as determined by experience, is usually from 85° to 88°, and the whole range admissible, under the varying conditions which sometimes occur, is not more than ten degrees,-namely, from 80° to 90°. If set below 80° the curd is long in coming, (unless an excess of rennet is added, which is highly objectionable,) is too tender, and the separation of the whey is attended with greater labor, and, unless extreme care is used, with loss also. If it be set at a temperature above 90°, the curd assumes a toughness which is objectionable, and the cheese made from it is hard and of inferior quality.

How shall the proper temperature be determined? My answer is, by the use of a thermometer,† and in no other way. The answer given by the practice of a majority of dairymen and dairywomen is, by the feelings, by judgment, by the verdict of a practiced hand; and doubtless they honestly believe these to be sufficient, and may ridicule the use of a scientific instrument to determine so simple a matter. But the truth is that feelings, though very useful in their place, are not to be depended upon to determine temperature. Our bodies are unconsciously affected by too many disturbing causes, to afford a reliable index to slight differences. Tell a man suffering from fever and ague that he is no warmer now, when seeming to be on fire, than he was a little while ago, when

*I could detect but little difference in the time required from 110 to 120 degrees, but above or below this point the time required was longer; and a degree of heat equal to 160 degrees or upwards seemed entirely to destroy the coagulating power of the rennet.

+ Many cheap thermometers seem like Pindar's razors, made to sell; but of late years the demand for and the manufacture of these instruments have greatly increased, and the price correspondingly diminished. A reliable one can now be had for seventy-five cents to a dollar at retail, or from five to eight dollars per dozen.

shivering under a heap of blankets, and unless he is assured of the fact by means of other evidence than his own sensations, he will believe you to be laboring under an egregious mistake; he may likely enough take you for a fool, and perhaps exclaim, "Don't I know when I'm burning and when I'm freezing!" and yet the fact is as you stated to him, and easily demonstrable by the introduction of the bulb of a thermometer beneath the tongue or under the armpit. A very simple experiment will satisfy any one that the sensation of cold or heat is not always, even when in perfect health, in consonance with the fact. Take two basins partly filled with water, one as hot as you can comfortably bear, and the other as cold. Plunge a hand in each, and after a little while pour one into the other and put both hands in it; one hand says the mixture is cold and the other says it is warm. No: if you desire a good product uniformly, and not merely occasionally, there is no other way but to use the proper means, to wit: the employment of an instrument acting by expansion and contraction in accordance with a fixed law, undisturbed by any of the many causes which affect living bodies.

How shall the desired temperature be attained? By heating, of course. But the way of doing this may affect the product. Milk should not be heated by the direct action of fire upon the vessel containing it. If a tub is used, the common method has been by warming the milk in a tin pail or other vessel set into a larger one of water to which the heat is applied. If this method is adopted the whole milk should be warmed, because if only a portion be heated, and that sufficiently to warm the rest to the proper degree, there is danger that some of the buttery portion will rise as oil and escape with the whey. If a tub must be used, the better way is to introduce a tin pail of hot water into the milk in the tub, and gently move it about. By a similar method—namely, by the using a pail of ice water, the evening's milk may be cooled, when to be kept over night in a wooden cheese tub in warm weather. In this way the proper temperature may be attained, and none of it heated too much. But the best way, by far, is to use the improved apparatus, consisting of a double vat, the inner one of tin containing the milk, and the outer one water, which is warmed by a fire of a few chips in the heater below. There are quite a number of these, differing somewhat in construction, several of them being well adapted to the purpose for which they are designed.

As good an one as any I have seen, and I think the best, is the one called the Oneida Vat, manufactured by W. Ralph & Co., Utica, N. Y., an illustration of which is here given:

The Engraving represents the tin or inner vat raised, and the sides of the outer vat broken out, to show the heater and supports of the inner vat.

A. Outer Vat which is lined with galvanized sheet iron.

B. Tin or inner Vat.

C. Copper Vat heater extending the entire length of the vat, and enclosed in a semi-cylindrical galvanized sheet-iron jacket; the heater surrounded by water, which water also fills the space between the vats.