Page:Defensive Ferments of the Animal Organism (3rd edition).djvu/48

 parts of the organism. To these belong all such substances as are received from the outside as nutriment, with the exception of those products which may be ranged amongst the most simple units, as, for instance, grape sugar. As substances "in harmony with the body," we would then term those which, when entirely recast, correspond in their structure to the essential composition of the particular species or individual. In addition to this general conception, which only means that a substance is not absolutely disharmonious to the body in general, we have undoubtedly to make a still finer distinction according to the special features of the compound in question. As early as the year 1906 we had suggested the advisability of distinguishing between substances which, though they are adapted to the blood, are nevertheless out of harmony with the varied cells of the body, and those which show any features characteristic of the structure of the cells of a particular organ. If our ideas concerning the structure of the particular cells of an organ, and the dependence of its functions on this peculiarity, prove correct, then it follows that, as we have already emphasized, each kind of cell must have at its disposal units of its own kind. We may then speak of substances that are "in harmony with" an organ,