SOME ALGAL GELATINES. 



Another series of analyses based on two samples gave the follow- 

 ing results : 



CaO 



MgO 



NasO 



K20 



Fe203+Al203 



Si02 



SO3 



P2O0 



AS2O3 



CI 



I 



Pentosans 



Galactan 



Solution in H2O at 20° C 



Solution in H2O at 100° C. . . . 

 Protein in alcohol precipitate 

 CO excess N HCl per gram 



Per cent. 

 0.17 

 (+) 

 3.236 

 21.40 

 18.9 

 95.9 

 1.30 



Agar-agar has been put to many uses, the number of which is in- 

 creasing from year to year. It has long been esteemed in China and 

 Japan as a food. It is employed in the preparation of jellies, thick- 

 ening of soups, ice cream, fruits, meat, or fish, and in candy making. 

 In this country it is used most extensively in hospitals and in bac- 

 teriological laboratories. As a base for culture media it is unexcelled 

 by any other substitute, since it remains solid with a smooth, firm 

 surface at the higher temperatures required for cultivating certain 

 species of bacteria. Other jellies are useless because they melt under 

 the requisite conditions. Recently it has been found to possess con- 

 siderable therapeutic value in the cure of chronic constipation. Its 

 action is dependent on the fact that it has the property of absorbing 

 and holding water, becoming at the same time a lubricant and mild 

 mechanical stimulant, affected but little by the digestive enzymes. 

 The action is not violent as with ordinary cathartics, and it leaves 

 no harmful aftereffects. It has also been found a valuable dressing 

 for certain types of wounds. Emulsions for photographic plates 

 much superior to the ordinary gelatin emulsions are claimed to 

 have been made. 



AGAR-AGAR RESOURCES OF THE UNITED STATES. 



A recent very incomplete survey of American seaweeds that 

 yield gelatin has brought to light another one of our valuable 

 natural resources that has been totally neglected. Up to the present 

 time we have been importing agar-agar, an essential product to our 

 general welfare, from countries thousands of miles distant, when a 

 superior product is to be had, probably for less cost, from algae 

 growing on our own shores. Even should the cost of production 

 prove to be more than that of the imported product, it is important, 

 as a step toward national security, to develop domestic sources of 

 supply. Of a dozen or more species of algae on the California coast 

 supposed to yield gelatin, the writer has been able to examine four 

 with the f ollowins: results : 



OELIDIUJr CARTILACxTNETTM, 



The species Gelidiuni cartilagineum was reported by an agent of 

 the Bureau of Fisheries as growing in abundance on the California 



