SALEP, PLANTAGO-PSYLLIUM (Flea-bane)
AND THE OTHER GELATINOUS BODIES.
Radix salep are called the dried tubers of several species of orchids, they are round, quite flat, yellowish white, horn-like, semi-diaphanous, very hard and without taste or smell. Formerly salep was imported mostly from Persia, but now the tubers of orchids grown at home are collected and do not in any way differ from those coming from Asia. They contain a good quantity of gum and on that account are used for finishing silks and for medicinal purposes. It is sold ground, or as powder and can be bought at every drug-store. As marbling size, salep possesses very excellent properties, similar to carrageen moss, but its high price prohibits its general application. In preparing size, use, to 6 quarts of water 2-1/2 ounces of powdered salep which must be well boiled for a long period so that it may become entirely dissolved. After standing 24 hours, it can be used in the same way, as carrageen size.
Plantago-Psyllium (Flea-bane, Flohsamen, Flohkrautsamen) is the seed of different species of Way Bread belonging to the family of the plantaginea viz., plantago-psyllium, Pl-Arenaria, Pl-Cynops, the second of which is found in Eastern Germany, Switzerland, Hungary, etc. on sandy fields, the other two on the sea-shores of southern Europe.
The seed is small with one side flat and the other concave and has a furrow upon which is located the eye or navel. It is lustrous and of a reddish brown color, the best varieties coming from southern France. In consequence of the great quantity of plant-mucilage or gum, that it contains, by treating with hot water a consistent mucilage or size is obtained and used in the manufacture of marbled paper and for finishing textile fabrics.
To prepare the size, place 4 ounces of flea-bane in a wide wooden tub, pour 6 quarts of boiling water over it and beat well with a switch of wicker-rods until the gum is entirely separated from the seeds, allow it to cool and after 10 or 12 hours filter through a linen cloth, when it is ready for use. The mucilage of flea-bane is quite homogeneous and of great consistency, is very viscous, forming strings very readily and is therefore not used for drawn edges since the colors will be drawn along by the stylus without being cut. It is mostly used for producing thickly veined, ordinary marbled edges, but flea-bane size is also much more expensive than that of carrageen moss and on the other hand its quality is so much inferior to that of the other that I cannot recommend it for use as size.
I will briefly mention the other vegetable matters containing an especially large quantity of gum or mucilage, but which have not come into use for preparing marbling size on account of their cost and of the less consistency of their mucilages.
The richest in this regard are the seeds of quinces and linseed. Their mucilage is as viscous as that of flea-bane. Much less gum is contained in the leaves of mallows of colts-foot or of marsh-mallows.
In closing this chapter upon the mucilages of plants and their applications as sizing for marbling I again recommend carrageen moss as the best size, because it has given me during my investigations and in practice, surprising results of its usefulness for all kinds of marbled edges.