to control, such as confusion in the filled milk legislation, the Powell case is authority for the validity of Congressional action in the Filled Milk Act. It involved a sale of an article assumed to be just as good as butter but which was prohibited because of its ingredients. In the Powell case, this Court said:
“The defendant then offered to prove by Prof. Hugo Blanck that he saw manufactured the article sold to the prosecuting witness; that it was made from pure animal fats; that the process of manufacture was clean and wholesome, the article containing the same elements' as dairy butter, . . . that the oleaginous substances in the manufactured article were substantially identical with those produced from milk or cream; and that the article sold to the prosecuting witness was a wholesome and nutritious article of food, in all respects as wholesome as butter produced from pure unadulterated milk or cream from unadulterated milk.” Pp. 681-82.
“It will be observed that the offer in the court below was to show by proof that the particular articles the defendant sold, and those in his possession for sale, in violation of the statute, were, in fact, wholesome or nutritious articles of food. It is entirely consistent with that offer that many, indeed, that most kinds of oleomargarine butter in the market contain ingredients that are or may become injurious to health. The court cannot say, from anything of which it may take judicial cognizance, that such is not the fact.....
“Whether the manufacture of oleomargarine, or imitation butter, of the kind described in the statute, is, or may be, conducted in such a way, or with such skill and secrecy, as to baffle ordinary inspection, or whether it involves such danger to the public health as to require, for the protection of the people, the entire suppression of the business, rather than its regulation in such manner as to permit the manufacture and sale of articles of that class