444 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1941 



Its principal use is in the finishing of straight grains and grain 

 upper leathers. When hides are split, the hair side is the grain 

 side, a somewhat rough leather of a very even quality. The re- 

 mainder of the split hide is uneven both in thickness and texture and 

 finds its principal use in the manufacture of inner soles. After tan- 

 ning is completed, the leather may be given one of several finishing 

 processes, one of which includes the use of Irish moss. The gelatin 

 is extracted from cured seaweed and then filtered for purification. 

 This gelatin is swabbed onto the leather with brushes, thereby giving 

 it body and stiffness. The leather is still dull in this state and must 

 be glazed to give it a polish, which is accomplished by rubbing it 

 with glass cylinders. Repeated glazing or the application of dress- 

 ing materials then intensifies the luster to a gloss. Irish moss gelatin 

 is used in shoe polishes, in which form it restores the finishes on worn, 

 scuffed leather. The dull finish given to the leather at the factory is 

 produced by revolving brushes on leather that has been treated 

 with Irish moss. 



The polishing effect of Irish moss is due to the ability of the 

 mucilage to smooth and hold down the tiny, rough projections on 

 the surface of unfinished leather. In this way grain leather is given 

 the luster which we see on our own shoes. Luster is not as important 

 as other qualities in the case of the inner soles, where Irish moss 

 is used as a filler to impart stiffness and body to the leather. The 

 gelatin of Irish moss is also used to impart body and luster and to 

 assist in the waterproofing of the very heavy retan leather used in 

 the soles and uppers of heavy footwear. One shoe manufacturer in 

 New England imports from Ireland about 12,000 pounds of Chondrus 

 crispu» a year. 



Agar and algin are also used in the treatment of leather. 



ALGAE AND THE PAPER INDUSTRY 



The Chinese in the olden days spread a little agar lightly over rice 

 paper to make it more durable. They also mixed it with lacquer to 

 strengthen paper, especially in the manufacture of fans and um- 

 brellas. Agar is used now to some extent in the manufacture of 

 paper as a paper coating, to impart resistance to penetration of 

 resin, wax, and grease. 



At various times processes of manufacturing paper from the giant 

 kelps have been proposed but apparently with no commercial success. 

 The cellulose obtained from the Laminariaceae bleaches easily and 

 under pressure becomes very hard so that it can be easily turned and 

 polished. A good tough paper can be made from it. 



Wlien dry, alginic acid assumes a hard, hornlike form that is very 

 insoluble and resistant to the action of chemicals. It may be used 

 for a substitute for horn and as an insulating material, 



