Abstract
When young rats are fed on mixtures of isolated food substances and inorganic salts such as the “protein-free milk” foods earlier described by the authors, 1 they cease sooner or later to grow and they then decline upon these diets. Milk food speedily brings restoration of growth; and it has been shown that the “essential” accessory factor responsible for this effect is a component of the cream which is present in butter. 1 Further experiments now indicate that the butter-fat separated by centrifugal methods from unsalted butter contains the substance which averts the cessation of growth and possible nutritive decline noted when lard is used instead of milk-fat.
Butter-fat thus prepared is free from nitrogen, phosphorus and ash-yielding constituents. The growth-promoting substance therefore is not a phosphatide (lecithin) or an inorganic compound.
Get full access to this article
View all access options for this article.