But new butter-casks require still more particular and careful treatment before they can be filled with butter without fear of injury. They are got ready for packing in several different ways. Some dairymen let them lie in pure water a whole summer and winter long, and wash them out in lye, and then treat them just as they do those that have been used. Others, however, who give the new casks the preference over the old, but who cannot wait for the soaking in lye over summer and winter, treat them in the following manner: They prepare a lye of good American potash, which generally contains the most alkali, in a cask holding some three hundred quarts, taking a pound of potash to twenty pounds of water. For a cask of the size named fifteen pounds of potash are used, which is prepared by pouring boiling water upon it and stirring constantly, adding a little more water as the potash dissolves. With this lye, which will be about five degrees strong by Beaumé’s aërometer, the butter-barrels are entirely filled. The barrels stand two hours filled with lye, and are then emptied and exposed to the air to dry, without being scoured out with water or milk. The lye may be used again for other new barrels, even though a part of its strength may be gone. Potash is added, from time to time, to keep up the specified degree of strength. A solution of fifteen pounds of coarsely-powdered alum is prepared in about three hundred quarts of hot water, in a vessel as large as the lye-cask. The butter-barrels are also filled full of the solution of alum, and allowed to stand twenty-four hours. This alum solution must also be of five degrees strength by Beaumé’s scale, and it can be used over and over by adding more alum now and then. After emptying out the alum and lye, they are dried a day in the sun and air, and then rinsed out in fresh, pure water, when they can be used for packing butter without fear. Some add a little sulphate of iron or green copperas to the alum, when the solution is more powerful; yet the management of the butter-barrels is then more troublesome, and requires more experience. The effect of the copperas has also the disadvantage that it blackens the barrels, which, though it does not injure them, is not liked by the purchaser. By this treatment the new butter-barrels are much more quickly and cheaply cleansed, and got ready for packing and transporting butter, than by the course pursued with old barrels. The barrels, treated as above, are not only quite water-tight, but the wood is stronger and more durable. By means of the potash-lye and the alum solution the tannin is taken from the oak-wood used in the barrels, which, if it remained, would give a disagreeable taste to the butter. The effect of the potash and alum upon the wood of the barrels is quite harmless, and does not impart the least unhealthy quality to the butter.