2-1/4 pints of milk contain about 45 grammes of proteid, whereas, according to the usual figures (125 x 6/10) a boy of this age requires 75 g. This quantity of 45 g. is however, higher, allowing for the boy's age, than that in several of the dietaries we have given in our table. A little consideration will show that Dr. Haig has overlooked the serious deficiency of the milk in the other constituents, which accounts for the boy's loss of weight. The quantity of milk contains only about 160 g. of total solid matter, whilst 400 g. is the necessary quantity. Milk is too rich in proteid matter to form, with advantage, the sole food of a human being. Human milk contains much less in proportion to the other constituents. The old doctrine enunciated by Justus von Liebig was that proteid matter is the principal source of muscular energy or strength. He afterwards discovered and acknowledged his error, and the subject has since been thoroughly investigated. The makers of meat extracts and other foods, either from their own ignorance of modern research or their wish to take advantage of the lack of knowledge and prejudice of the public, call proteid matter alone nourishment. The carbo-hydrates and fats are equally entitled to be called nourishment. Our reason for devoting so much space to the consideration of the quantity of proteid matter required, is that in the opinion of many eminent writers it is the crux of vegetarianism. They have stated that it is impossible to obtain sufficient from vegetable foods alone, without consuming an excessive quantity of carbo-hydrates. We will summarise the argument as given in Kirke's Physiology, as edited by Morrant Baker, a standard work, and which is repeated in Furneaux's "Animal Physiology," a book which is much used in elementary science schools: "The daily waste from the system amounts to, carbon 4,500 grains (or 300 grammes), and nitrogen, 300 grains (or 20 grammes). Now let us suppose a person to feed on bread only. In order to obtain the necessary quantity of nitrogen to repair this waste he would have to eat nearly 4-1/4 lbs. daily.... He would be compelled to take about double the quantity of carbon required in order to obtain the necessary weight of nitrogen.... Next, let us suppose that he feeds on lean meat only. Then, in order to obtain the necessary quantity of carbon, he must eat no less than 6-1/2 lbs. daily.... In this case we notice a similar waste of nitrogen, the removal of which would give an undue amount of work to the organs concerned.... But it is possible to take such a mixed diet of bread and meat as will supply all the requirements of the system, and at the same time yield but little waste material." (These extracts are from Furneaux, the next is from Kirke. The figures and argument is the same in each, but we have chosen those sentences for quotation which are the briefest and most suitable; certain calculations being omitted.) "A combination of bread and meat would supply much more