152 Report S.A.A. Advancement of Science. 



their fine texture and somewhat coherent character would render ant- 

 heaps too close and impervious to yield a good soil by themselves, but 

 by mixing them with a sandy soil this could readily be remedied. 



B. Ammonium Salts. These, which are in Europe produced as 

 bye-products in the distillation of coal and shale, are not made in 

 any quantity here. Very little coal is used for gas-making, so that 

 the amount of ammonium salts produced in the Colony must be 

 insignificant. Moreover, in the case of many of our soils, deficient 

 as they are in lime, these substances would not be very suitable unless 

 a dressing of lime were previously applied. 



C. Nitrates. Unfortunately few authentic cases of the occur- 

 ence of nitrate deposits are known in the Transvaal. I have had 

 several saline deposits sent from various localities for examination, in 

 the hope that they would be found to consist largely of nitrate of 

 soda or potash, but none have been found to be of any value. A 

 deposit was reported to have been discovered in the Zoutpansberg 

 about a year ago, but I have not been able to obtain any information 

 concerning it. I am told that many of the older farmers in the 

 Colony speak of " saltpetre " occurring in crystals on stones in the 

 neighbourhood of pans, but I have not been able to ascertain whether 

 the substance so called is ever really saltpetre, i.e., potassium 

 nitrate. If such deposits do occur, it is very important, since nitrate 

 of potash or soda would be of immense service in agriculture, 

 provided its price were reasonable. The cost of the imported South 

 American product is very high in this country on account of freight 

 and transport charges. 



At present, unless the farmer is willing to pay the very high 

 prices for imported nitrate of soda or sulphate of ammonia, he must 

 chiefly depend for nitrogenous manuring upon organic matter, kraal 

 and stable manure, bucket refuse, carcasses of animals, bats' guano 

 and kindred substances, or adopt the plan of enriching the soil by 

 the growth of leguminous crops and so obtaining nitrogen from the 

 air. 



2. — Phosphoric Acid. 



A. Bones. There are considerable quantities of bones avail- 

 able in the Colony. In additon to those of animals slaughtered for 

 food, there are the bones and bodies of those which die from disease ; 

 unfortunately, these have been only too numerous in late years. Then, 

 too, large quantities of bones occur scattered over the veld as relics 

 of the horses, mules, and oxen which died during the war. 



Bones, when reduced to fine powder, form a valuable though 

 somewhat slow-acting manure, and might with advantage be largely 

 employed in agriculture here. 



The carcasses of animals which die from disease might, as a 

 preventative of the spread of contagion, be burnt in a suitable 

 furnace, and the residue would form a valuable phosphatic manure. 

 A sample of such " ash " from the crematorium at the Veterinary 



