The Pectic Substances of Plants

The substances known as the pectins, which are said to form the middle lamella of plant cells, offer many points of interest. It is supposed that they are readily attacked by various fungi which are the causes of plant diseases, and a knowledge of their chemistry is, therefore, of considerable importance to plant pathologists. They also, under certain conditions, which are not yet clearly understood, form gels, and it was mainly the interest in this particular property which first attracted the authors of this paper to' their investigation. One of them (S. B. Schrvver) had already commenced a systematic chemical research, when the other [Haynes 1914] published a paper dealing with the conditions under which pectic gels were formed, and they decided to continue in partnership their researches, which have, unfortunately, been repeatedly interrupted by other work.