BIOLOGY AND NATURAL HISTORY 235 



important from the standpoint of amount consumed, as shown in Table i. 



* Figures are per annum consumption of a typical pre-war year. 



The uses for agar may be classified as follows: 



FOODS. In fruit cakes, fruit puddings, icings, pie fillings, meringues, and 

 cheeses to control moisture content and to modify texture; in mayonnaise 

 and salad dressings as a thickener and stabilizer; in confections, especially 

 jelly candies and marshmallows; in aspic type salads to provide a gelatinous 

 matrix; in place of pectin in jellies, jams, and preserves; in canned meats 

 such as fish, poultry, and tongue to prevent the product from becoming 

 mushy during transit; in casings for sausages and wieners. 



PHARMACEUTICALS. Probably the best known use of agar is as "roughage" 

 or bulk in constipation therapy. It is also used to stabilize emulsions; to 

 solidify some glycerin suppositories; to make a formaldehyde gel for fumi- 

 gation; in wound dressings to absorb moisture or provide a constant rate 

 of release of antiseptics or antibiotics; as pill coating, especially to control 

 time of release or rate of availability of a drug; as a vehicle in which a drug 

 is incorporated so that there is a slow release of a therapeutic agent during 

 its entire passage through the body. 



MOLDING COMPOUND. Agar is the principal constituent of some of the best 

 dental impression materials, as it is fluid at a temperature that does not 

 burn the mouth, but will gel at a temperature slightly above that of the 

 body. Its elasticity permits removal of the agar mold from undercuts with- 

 out breaking or distortion. It is used in a similar manner for other types 

 of molding work, such as the making of artificial hands. 



INDUSTRIAL USES. Agar is used as a suspending agent for graphite lubri- 

 cants of dies in drawing tungsten wire for light bulbs and electronic tubes; 

 in place of gelatin as a vehicle for photographic emulsions; in hectograph 

 duplicators; as an activator of nicotine sprays; in storage batteries for 

 submarines; occasionally in tobacco to control moisture; to coat humus 



