ON THE CONSTITUENTS OF THE TISSUE OF FUNGI.
(p. 87) These two communications are a contribution of fundamental importance, and may be regarded as placing the question of the composition of the celluloses of these lowest types on a basis of well-defined fact. In the first place the author gives an exhaustive bibliography, beginning with the researches of Braconnot (1811), who regarded the cellular tissue of these organisms as a specialised substance, which he termed 'fungin.' Payen rejects this view, and regards the tissue, fully purified by the action of solvents, as a cellulose (C6H10O5). This view is successively supported by Fromberg [Mulder, Allg. Phys. Chem., Braunschweig, 1851], Schlossberger and Doepping [Annalen, 52, 106], and Kaiser. De Bary, on a review of the evidence, adopts this view, but, as the purified substance fails to give the characteristic colour-reactions with iodine, he uses the qualifying term 'pilzcellulose' [Morph. u. Biol. d. Pilze u. Flechten, Leipzig, 1884].
C. Richter, on the other hand, shows that these reactions are merely a question of methods of purification or preparation [Sitzungsber. Acad. Wien, 82, 1, 494], and considers that the tissue-substance is an ordinary cellulose, with the ordinary reactions masked by the presence of impurities. In regard to the lower types of fungoid growth, such as yeast, the results of investigators are more at variance. The researches of Salkowski (p. 113) leave little doubt, however, that the cell-membrane is of the cellulosic type.
The author's researches extend over a typical range of products obtained from Boletus edulis, Agaricus campestris, Cantharellus cibarius, Morchella esculenta, Polyporus officinalis, Penicillium glaucum, and certain undetermined species. The method of purification consisted mainly in (a) exhaustive treatments with ether and boiling alcohol, (b) digestion with alkaline hydrate (1-2 p.ct. NaOH) in the cold, (c) acid hydrolysis (2-3 p.ct. H2SO4) at 95°-100°, followed by a chloroxidation treatment by the processes of Schulze or Hoffmeister, and final alkaline hydrolysis.
The products, i.e. residues, thus obtained were different in essential points from the celluloses isolated from the tissues of phanerogams similarly treated. Only in exceptional cases do they give blue reactions with iodine in presence of zinc chloride or sulphuric acid. The colourations are brown to red. They resist the action of cuprammonium solutions. They are for the most part soluble in alkaline hydrate solution (5-10 p.ct. NaOH) in the cold. They give small yields (1-2 p.ct.) of furfural on boiling with 10 p.ct. HCl.Aq.
Elementary analyses gave the following results, which are important in establishing the presence of a notable proportion of nitrogen, which has certainly been overlooked by the earlier observers:—
| 'Cellulose' or residue from | C | H | N |
| Boletus edulis (Schulze process) | 42.4 | 6.5 | 3.9 |
| Boletus edulis (Hoffmeister process) | 44.6 | 6.3 | 3.6 |
| Polyporus off. | 43.7 | 6.5 | 0.7 |
| Cantharellus cib. | 44.9 | 6.8 | 3.0 |
| Agaricus campestris | 44.3 | 6.6 | 3.6 |
| Botrytis | 42.1 | 6.3 | 3.9 |
| Penicillium glaucum | — | — | 3.3 |
| Morchella esculenta | — | — | 2.5 |
It is next shown that this residual nitrogen is not in the form of residual proteids (1) by direct tests, all of which gave negative results, and (2) indirectly by the high degree of resistance to both alkaline and acid hydrolysis. The 'celluloses' are attacked by boiling dilute acids (1 p.ct. H2SO4), losing in weight from 10 to 23 p.ct., the dissolved products having a cupric reduction value about 50 p.ct. that of an equal weight of dextrose. As an extreme hydrolytic treatment the products were dissolved in 70 p.ct. H2SO4, allowed to stand 24 hours, then considerably diluted (to 3 p.ct. H2SO4) and boiled to complete the inversion. The yields of glucose, calculated from the cupric reduction, were as follows:—
| Boletus edulis | 65.2 | p.ct. |
| Polyporus off. | 94.7 | " |
| Agaricus campestris | 59.1 | " |
| Morchella esculenta | 60.1 | " |
| Cantharellus cib. | 64.9 | " |
| Botrytis | 60.8 | " |
It will be noted that the exceptionally high yield from the Polyporus cellulose is correlated with its exceptionally low nitrogen. By actual isolation of a crystalline dextrorotary sugar, by preparations of osazone and conversion into saccharic acid, it was proved that dextrose was the main product of hydrolysis. The second main product was shown to be acetic acid, the yield of which amounted to 8 p.ct. in several cases.