Plate VII. exhibits the appearance of butter, oleomargarine, beef, and some other fats, when viewed by the microscope and polarised light. It will be noticed that, while a discrimination between lard and butter is readily made, oleomargarine presents the St. Andrew’s cross, stated to be characteristic of genuine butter. These photomicrographs represent the results of investigations made in the Chemical Division of the U.S. Department of Agriculture.
The question of the sanitary effects of oleomargarine and other substitutes for butter, has been studied by many scientists, and with very discordant results. Doubtless the great divergence of opinion which at present exists, is largely due to the fact that the artificial products examined have been made according to different processes, and with varying regard to the quality of the fats used in their manufacture, and to the degree of care and cleanliness observed. The attention of the American public has very lately been directed to the oleomargarine question, by the recent enactment of a national law imposing a tax upon the manufacture of the article.
Without entering to any great extent into the subject of the wholesomeness of artificial butter as it is generally met with in commerce, it will be of interest to refer to the conclusions reached by two or three sanitarians who have devoted particular attention to this aspect of the question. Prof. W. O. Atwater[43] summarises the results of his investigation of oleomargarine as follows:—
“1. The common kinds of imitation butter, oleomargarine, butterine, etc., when properly made, agree very closely in chemical composition, digestibility, and nutritive value with butter from cow’s milk.
“2. In fulfilling one of the most important functions of food, namely, that of supplying the body with heat and muscular energy, they, with butter, excel in efficiency all, or nearly all, our other common food materials.
“3. Considering the low cost at which they can be produced, as well as their palatability and nutritive value, they form a food product of very great economical importance, and one which is calculated to greatly benefit a large class of our population whose limited incomes make good dairy butter a luxury.
“4. Imitation butter, like many other manufactured food materials, is liable (but in actual commerce has been found not to be so) to be rendered unwholesome by improper materials and methods of manufacture. It is also open to the especial objection that it is largely sold as genuine butter. The interests of the public, therefore, demand that it should be subjected to competent official inspection, and that it should be sold for what it is, and not as genuine butter.”
Dr. S. B. Sharples[44] states: “When well made, it (oleomargarine) is a very fair imitation of genuine butter; being inferior to the best butter, but much superior to the low grades of butter too commonly found in the market. So far as its influence on health is concerned, I can see no objection to its use. Its sale as genuine butter is a commercial fraud, and as such, very properly condemned by the law. As to its prohibition by law, the same law which prohibited it should also prohibit the sale of lard and tallow, and more especially all low-grade butters, which are far more injurious to health than a good sweet article of oleomargarine. A good deal has been said in regard to the poor grade of fats from which the oleomargarine is made. Any one making such assertions in regard to the fats is simply ignorant of the whole subject. When a fat has become in the least tainted, it can no longer be used for this purpose, as it is impossible to remove the odour from the fat after it has once acquired it.”
Per contra, Dr. R. B. Clark, in an exhaustive report on butter,[45] affirms with great decision, that artificial butter is not a wholesome article of food, for the following reasons:—