There are several kinds of vitamines. Some are associated with the bran of cereals, other with the juices of fruits. Some are easily destroyed by heat, while others survive a boiling temperature. The discovery of vitamines must stand as one of the most masterly achievements of modern science, even outshining in brilliancy the discovery of radium. It was only by the most persevering efforts and the application of all the refinements of modern chemical technic that the chemist, Funk, was able to capture and identify this most subtle but marvelously potent element of the food. This discovery has cleared up a long category of medical mysteries. We now know not only the cause of beri-beri and scurvy and the simple method of cure by supplying vitamine-containing foods, but within a very short time it has been shown that rickets and pellagra are likewise deficiency diseases, probably due to lack of vitamines, and in a recent discussion before the New York Academy of Medicine by Funk, Holt, Jacobi and others, it was maintained that vast multitudes of people are suffering from disorders of nutrition due to the same cause. Osborne a few years ago conducted experiments which demonstrated that something more than pure food elements and salts is essential for growth and development. They found that rats fed on starch and fat lived only four to eight weeks. When protein was added they sometimes lived and grew and sometimes remained stunted or died. It was thus evident that proteins differ. Their observations proved very clearly that there are perfect and imperfect proteins. The protein of corn, zein, for example, was shown to be incapable of supporting life. With the addition of a chemical fraction, tryptophan, obtained from another protein, the rats lived, but did not grow. By adding another fractional protein, lysin, the rats were made to thrive. A minute study of the subject by Osborne, Mendel and numerous other physiologic chemists have shown that a perfect protein is composed of more than a dozen different bodies called amino-acids, each of which must be present in the right proportion to enable the body to use the protein in body building. Each plant produces its one peculiar kind of protein. The protein of milk, caseine, is a perfect protein. Eggs and meat, of course, supply complete proteins, but among plants there are many imperfect proteins. McCollum has demonstrated that grains, either singly or in combination will not maintain life and growth. The same is true of a mixture of grains with peas or navy beans. Another element is lacking which must be supplied to support life and growth.