subjects himself to information from any of his servants, who must no doubt discover it, and thus loses all command over them.
No respectable house, therefore, will now run any such risks, and we would strongly recommend it to all, never to be influenced by the opinions of ignorant quacks, who, knowing nothing about the matter, care only for their own interest.
Heading.
There is, however, one ingredient, called heading, that gives to porter a fine frothy top, which adheres to the pot or glass, when pouring out, or drinking the beer. It is sulphate of iron, commonly called salt of steel, which, when applied in such small quantities as will have the desired effect, can do no harm. One ounce of this is enough for four barrels; or one quarter of an ounce to a barrel.
This heading also imparts to the beer a sharpness in taste, generally liked by porter drinkers. The law, however, has imposed severe penalties on the use of it, and a test is applied for detecting its presence. The test alluded to is the red ferro-cyanide of potassium. As it is not a substitute for either malt or hops, and as people generally prefer porter carrying a good head, there can be no good reason for its being so severely prohibited.
