54- LOOG-AS. 



2. The action of the alkahne carhonates on prolonged boiling is to 

 split the fat into glycerine and fatty acids, which latter, reacting with the 

 alkaline carbonates, form sodium and potassium salts of the fatty acids, 

 viz., soaps. 



3. The addition of salt causes the separation of the soap curd from 

 the glycerine-containing liquid, while during the subsequent boihng, some 

 of the potassium soaps are converted into sodium soaps which ensures 

 the end jn-uduct being a hard soap instead of a possible soft one. 



In some cases the method used includes the addition of 

 slaked lime as follows : — 



25 lb. of fat. 

 I Bucket of ash. 

 I Plate of slaked lime. 



The ash and slaked lime are boiled with water as in the 

 former process. The soap making in this process, however, 

 takes only about 30 hours' boiling. The explanation is that by 

 the addition of slaked lime to the ash and the subsequent boiling 

 caustic soda and potash are formed, and these are able to 

 " split " the fat much more easily than the carbonates. 



To return to the purpose of this paper. At the present 

 time " loog as" is undoubtedly a valuable product; but the 

 main question requiring answer i> this : " Is it not possible in 

 normal times to make still more profitable uses of the ash bush 

 than those of soap-making and manuring?" 



It would seem to the writer that it should be simple and 

 practicable to obtain almost pure sodium and potassium car- 

 bonates from "loog as," or even to transform them into nitrates 

 and cyanides. 



The evaporations of the extracts could be carried out 

 largely by the heat obtained on burning the bush itself and other 

 useless vegetation. Besides this, the sun is hot in the Karroo 

 and the air is extremely dry. It would, therefore, appear that 

 the concentration of the extract would prove a simple matter. 



So simple does the process appear that it is suggested to 

 chemical manufacturers that the utilization of " loog as " is 

 worthv of their serious consideration. 



In conclusion, thanks are tendered for valuable assis- 

 tance rendered by. and information obtained from Messrs. 

 Thornton, van der ]\Ierwe. Lamont, and M. Lundie, of the 

 Government School of Agriculture, Grootfontein, to Mr. Pole 

 Evans, of the Botanical Division, De])artment of Agriculture, 

 and to Mr. Stahl, Mayor of ^liddelburg). 



Martian Seas. —The Rev. \\'. F. A. ElHson, in the 

 Joitnial of the Brifish Asironomical Association, directs atten- 

 tion to the significance of the low albedo of the darker parts of 

 Mars. He is of opinion that their albedo cannot be far from 

 zero, and points out that we know nothing capable of so eating 

 up light as to reflect practically none of it except a deep layer 

 of something transparent. He therefore considers the evidence 

 irresistible that the dark areas on Mars consist of deep water. 



