USEFUL ALGAE — CHASE 441 



Irish moss sometimes gives a harsh feeling to thread, provided all 

 the salt has not been removed from the moss by a preliminary steep- 

 ing in water. Irish moss is used to thicken dye solutions for use in 

 printing calico. A process of treating Irish moss extract with 

 formaldehyde in order to make the dried size insoluble has been 

 patented. Algin has been used for fixing mordants and is a sub- 

 stitute for various salts formerly used in fixing mordants previous 

 to the dyeing of cottons and yarns. 



Algin or sodium alginate is a very useful alginate since it is 

 easily soluble in water and can be readily changed into soluble sub- 

 stances. For this reason it is valuable as a sizing substance. It is 

 superior to starch in this use as it fills the cloth better, is tougher, 

 more elastic and, since its solutions are very viscous, it goes farther 

 than starch or any gum. As soon as the sodium alginate has impreg- 

 nated the cloth it may easily be made insoluble by treatments with 

 dilute acids, lime water, salts of calcium, barium, and various other 

 metals. It can be used as a fixer for mordants in fabrics and to some 

 extent as a mordant. Ammoniated aluminium alginate can be used 

 for the preparation of waterproof fabrics since it becomes insoluble 

 after drying. 



In November 1938 the Department of Commerce received the 

 notice of a new mucilage product made from Chondrus crispus, 

 Ohondrus elatus, Gigartina tenella^ Grateloupia fHidna, Grateloupia 

 flabellata, Hypnea seticulosa, and other seaweeds. The mucilage 

 from them is high in adhesive content and low in price. The 

 mucilage is produced by washing the seaweed in fresh water, remov- 

 ing the salt, adding a definite quantity of water, and the effecting 

 of certain physical and chemical treatments, the details of which are 

 not divulged. The solution is made highly viscous and its solidifying 

 property is reduced. The product is said to be high in solubility 

 and a concentrated solution of more than 30 percent can be produced. 

 The invention is significant in view of the appreciable imports of 

 mucilage from abroad. Its use is very extensive in the special proc- 

 essing of textiles, for stickers in general, for the production of 

 printing materials, and other uses. 



In ancient times the seaweeds were used in dyes. There were 

 certain ones that had the reputation of clearing the colors and mak- 

 ing them more brilliant and intense, especially those that were used 

 as red dyes. The ancients used Fiicus which they called "red fucus" 

 or "dyer's fucus" to dye their draperies and other linen materials. 



By nitrating alginic acid, Nettlefold prepared a brown dye that 

 is suitable for dyeing unmordanted cotton. This unmordanted cot- 

 ton dyed a fine Bismarck brown color which was more fast to soap 

 than many alkaline colors, equaling chrysoidine. The depth of the 



