Various kinds of vessels have been recommended for milk, and they have been made of lead, zinc, slate, and other materials. China are the best; but the old-fashioned wooden or earthenware pans appear to be the most general favourites; the only objections being, that wooden pans require a great deal of care to keep them clean, and that the leaden glaze of the earthenware pans is apt to be affected by the acid of the milk, if it should be kept till it becomes sour. No good dairy-maid, however, would ever keep milk in her pans till it became acid: and, if by any chance wooden vessels became tainted by having had in them sour or otherwise spoiled milk, they should be soaked in water in which a large piece of soda has been dissolved; and, if this does not sweeten them, they must be boiled in soda and water, and then immersed in pure cold water for a day or two. Milk when drawn from the cow is warm, and it should be set up in the dairy before it is quite cold, or the _Cream_ will not rise properly. Cream for butter may stand twelve hours on the milk, but the cream that rises in two or three hours after the milk is set is considered the richest. In many places the milk is skimmed twice, the second time twelve hours after the first; but the second skimming is considered very inferior to the first. In Devonshire, the dairy-maids set the milk-pans on a hot hearth, in order to raise the rich cream peculiar to that county. In Scotland, _Butter_ is made by churning the whole of the milk, which is put into the churn as it comes from the cow, and kept there till it is slightly sour before it is churned; but this makes the operation of churning very laborious, and the butter has always a sour taste. In England, butter is made only from the cream, which is not put into the churn till wanted for churning, but is kept previously from three days to a week in a deep earthen vessel, and is stirred every day when fresh cream is put in. Churns are of two kinds, viz. the plunge-churn, the motion of which is up and down; and the barrel-churn, which turns round, and is considered much the best. Churning is generally performed in the open air in summer, and in the dairy scullery near the fire in winter. If kept too cold, the butter will not "come;" and, if too hot, the butter will be soft, and will soon become rancid.