USEFUL ALGAE — CHASE 443 



was given to the ashes of the burnt kelp in France because 

 of its resemblance to the commercial product and its method of 

 manufacture. 



In 1692 Louis XIV gave to the Koyal Company of Glass Manu- 

 facturers at Paris the sole privilege of cutting from March 15 to 

 September 15 of each year for 20 years all the kelp along the coast 

 of La Hogue for the production of kelp ashes, and allowed them to 

 transport these kelp ashes to Paris. This law was revoked in 1718 

 by demand of the Normans who wished the kelp for fertilizers and to 

 bum for iodine. In the glassworks all the ashes were used, since the 

 portion of fixed alkali which was already in combination with the 

 organic matter was in a state that acted as a melter for the other 

 clays and sands which entered into the composition of glassware. 

 For this reason kelp ashes were used with great success and to great 

 advantage in the glass and porcelain works where common glassware 

 was manufactured, especially in Normandy. 



Funori or seaweed glue is used in the decorating of porcelains in 

 Japan. 



Algin is used as a binder and plasticizer in ceramics. 



Mertle writes that Irish moss has been suggested as a substitute 

 for fish glue in the preparation of bichromated enamel, but it has 

 never been popular owing to the greater uniformity of results 

 obtained with glue mixtures. 



About 25,000 pounds of Irish moss is used each year by the paint 

 industry in the making of cold-water or casein paints. Irish moss 

 is used as a stabilizer to give the casein coloring matter and water 

 consistency, and to hold the film in place while the casein hardens. 

 Casein paints treated with Irish moss brush well and hold to the 

 surface while they dry. Ghondrus crispus is used in preference to 

 other gums because of its cheapness, its thick consistency in extremely 

 low concentrations, and its transparency, which keeps it from inter- 

 fering with the color of the paint. Agar has been substituted for 

 fish glue in process enamels to a slight extent. 



Algin is used as a suspending, emulsifying, and bodying agent in 

 water paints, resin emulsion paints, and other special types of paints. 



ALGAE AND TANNING 



In the early part of the nineteenth century the French gold beaters 

 used supple gold-beater's skins to reduce the gold into thin leaves. 

 Isinglass or fish glue was used to give the luster which the tanning 

 removed. The animal substances cracked under the repeated blows 

 of the wooden hammers. A Parisian manufacturer replaced the 

 isinglass by agar and found he achieved better results. Irish moss or 

 Ghondrus crispus is used in the tanning industry, as it imparts to 

 certain types of leather a gloss and a stiffness that is very desirable. 



