group forms around the nucleus known to chemists under the name of pyrrol. The fourth comprises bodies such as the glucoproteins, connected with the sugars, or carbohydrates.
Does the fact that the molecule of albumin is destroyed in producing these compounds raise the question as to whether it implies the idea that in reality they pre-exist in it? Chemists are rather inclined to admit this. However, the conclusion does not appear to be permissible. Duclaux considers it doubtful. It is not certain that all these fragmentary bodies pre-exist in reality, and it is no more certain that a simple bringing of them together represents the primitive edifice. Materials of demolition from a house that has been pulled down give no idea of its natural architectural character. There is only one way of justifying the hypothesis, and that is to reconstitute the original molecule of albumin by bringing the fragments together. We have not got to that stage yet. The era of syntheses of such complexity is more or less near, but it has certainly not yet begun.
Moreover, it is not correct to say that the simple juxtaposition of the surfaces of fracture will reproduce the initial body. The fragments, so far as analysis has obtained them, are not absolutely what they might have been in the original structure. There they adhered the one to the other, not only by the mere contact of their surfaces of fracture, as is supposed, but in a slightly more complex manner. The fragments of the molecule are joined by bonds. We can picture them to ourselves by supposing these bonds to be like hooks. The hooks, which could only be broken by violence, are called by the chemists
