END NOTES ----- Footnote 1: From circular No. 85 of a series of statements prepared under the direction of the Secretary of Agriculture, covering the agricultural situation for 1918. Footnote 2: _The Babcock Test_ is operated as follows: When the milk has been thoroughly mixed and a true sample has been taken the _pipette_ is filled to the mark by sucking the milk into it until it stands a little above the mark on the stem, then quickly placing a dry finger over the end of the pipette and allowing the milk to escape until it just reaches the mark. The quantity thus measured off is 17.6 c.c. The pipette is then emptied into the _test bottle_ by placing the point in the neck and allowing the milk to flow slowly down the inside of the neck, taking care not to lose any of the milk. Blow the last drops out of the pipette into the bottle. The _measuring glass_, holding 17.5 c.c., is filled to the mark with _sulphuric acid_ of a specific gravity of 1.82 to 1.83 and this is poured into the milk in the test bottle. The acid is a strong poison and must be handled with care. Pour it slowly down along the wall of the bottle which is held at an angle and turned slowly during the operation. Now give the bottle a rotary motion to thoroughly mix the milk and the acid, shaking vigorously towards the end of the operation so as to be sure not to leave any of the acid which is heavier than the milk at the bottom of the bottle. _Whirling._—The bottles are then placed in the centrifugal machine and whirled for five minutes at the proper speed—from 600 to 1200 revolutions per minute—according to the diameter of the machine and as stated in the directions which come with the tester. The mixture of milk and acid is hot enough if the whirling is done at once, but if it is allowed to cool the bottles should be placed in hot water of 150 to 170° for about 15 minutes; whirling at full speed for 4 minutes brings all the fat to the top. Hot water is now added until the bottle is filled almost to the scale on the neck and the bottles are again placed in the machine and whirled at full speed for one minute. Hot water is then again added until the lower end of the fat column is within the scale, preferably at the 1% or 2% mark on the neck of the bottle. Whirl once more for one or two minutes and then read off the percentage of fat on the scale. Each division represents 0.2% fat. The fat column is measured from the lower line between the fat and the water to the point where the top of the fat column touches the wall of the neck. A pair of dividers are handy for measuring the fat column and reading off the percentage of fat in the milk. The bottle with contents should be warm—about 140°—when the measure is taken.