has a limited capability of
substituting dextrin. The suggestion to employ the evaporated extract as
a reducing agent in indigo dyeing and printing has also proved
unfruitful. The author's application of the soda salt of the lignone
sulphonic acid as a reducing agent in chrome-mordanting wool and woollen
goods (D.R.P. 99,682) is more successful in practice, and its industrial
development shows satisfactory progress. The product is known as
'lignorosin.'

FOOTNOTES:

[10] See more particularly: Lindsey and Tollens, _Annalen_, 267, 341;
Cross and Bevan's _Cellulose_, pp. 197-203; Street, Inaug.-Diss.,
Goettingen, 1892; Klason, _Rep. d. Chem. Ztg._ 1897, 261; Seidel and
Hanak, _Mitt. d. Techn. Gew. Mus._ 1897-1898.

SECTION VII. PECTIC GROUP

UNTERSUCHUNGEN UeBER PECTINSTOFFE.

R. W. TROMP DE HAAS and B. TOLLENS (Lieb. Ann., 286, 278).

UeBER DIE CONSTITUTION DER PECTINSTOFFE, B. TOLLENS (ibid. 292).

~INVESTIGATIONS OF PECTINS.~

(p. 216) It is generally held that the pectins are, or contain, oxidised
derivatives of the carbohydrates. The authors have isolated and analysed
a series of these products, and the results fail to confirm a high
ratio O : H. The following are the analytical numbers:

________________________________________________
| | | | | |
| Pectin from | Ash | C | H | Ratio H : O |
|______________|______|______|_____|_____________|
| | | | | |
| Apple | 6.2 | 43.4 | 6.4 | 1 : 7.9 |
| Cherry | 20.5 | 42.5 | 6.5 | 1 : 7.9 |
| Rhubarb | 4.2 | 43.3 | 6.8 | 1 : 7.4 |
| Currant | 5.0 | 47.1 | 5.9 | 1 : 8.5 |
| Greengage | 3.3 | 43.0 | 5.9 | 1 : 8.5 |
| Turnip | 7.3 | 41.0 | 5.9 | 1 : 9.0 |
|______________|______|______|_____|_____________|

Acid hydrolysis (4 p.ct. H_{2}SO_{4}) gave syrupy products not
crystallisable--in certain cases the hydrolysis was accompanied by
separation of insoluble cellulose. The insoluble product from currant
pectin had the composition C 54.4, H 5.0.

Tollens points out that the results of empirical analysis are
inconclusive; and that from the acid reactions of these products and
their combination with bases, carboxylic groups are present, though
probably in anhydride or ester form.

The pectins may be regarded as closely related to the mucilages
(_Pflanzenschleim_), differing from them only by the presence of the