The liver is on the direct channel of absorption of carbohydrates and proteids, and its connection with the metabolism of these substances has been fully demonstrated.

It is not on the channel of absorption of fats, and its relationship to the metabolism of fats has never been systematically investigated.

The object of the present research is to elucidate this question.

The first part of the paper is concerned with an investigation into the methods of estimating the fats. It is shown that after complete extraction with ether, by treating the residue with hydrochloric acid and heat, a further amount of material may be extracted by ether, but that it is impossible to say how far this is composed of the fatty acids previously combined with bases as soaps, and how far from the decomposition of nuclein bodies. The present research, therefore, is concerned simply with the fats extracted by ether.

It is next shown that the ether extract is no fair measure of the amount of fats present, since it contains on an average only 57 per cent. of fatty acids. In estimating the amount of fats, it is necessary to determine the fatty acids, and not merely the ether extract. The fatty acids amount to between 2 and 3 per cent. of the liver substance.

In the liver the proportion of palmitic and stearic acids to oleic acid is shown to be markedly higher than in the fats of the rest of the body. Hence the liver fat has a high melting-point.