FARMING BY DYNAMITE. HI 



indeed, that it is seldom done in South Africa. Breaking through 

 the practically waterproof stratum with dynamite is just as effec- 

 tive, and much cheaper. Here, again, however, we shall have to 

 await results before any general scheme can be outlined. 



This is not the place to describe how the various simple 

 operations of preparing the charge, making the holes and then 

 charging them, are carried out. Any person of ordinary intelli- 

 gence can learn all that has to be learned in a very short time, 

 and if common sense is used, there need not be the slightest 

 danger to any operators. 



Some may be curious as to the kind of dynamite which is 

 used for these operations, but there is really no great secret about 

 it. It is what is called a " slow explosive," i.e., slow in exerting 

 its explosive effects. The composition which my company re- 

 commends is one which contains 35 to 40 per cent, nitro-glycerine, 

 the balance being made up of nitrates and wood pulp. The 

 quicker and stronger explosives, such as blasting gelatine, and the 

 old kieselguhr dynamite which was formerly used in the Kim- 

 berley mines, would be quite useless for the processes which have 

 been described. In most cases they would only make a little 

 crevice at the botom of the bore-hole, and would certainly not 

 give the heaving and rending effects which are necessary. They, 

 too, however, have their application in the removal of boulders 

 and the making of roads and cuttings, but these operations are 

 just a little outside the scope of these notes — which have been 

 written with the sole object of arousing interest. 



BlPHOSPHATE. — Under this name a new fertiliser is 

 being prepared at the Notodden Nitrate Works in Norway, by 

 dissolving raw phosphates, such as Apatite, in nitric acid pre- 

 pared from the nitrogen of the atmosphere. The Chemical Trade 

 Journal states that a sample of Diphosphate, analysed on arrival 

 in London, contained 26 per cent, of phosphoric acid and 23.8 

 per cent, of calcium nitrate. 



Poisoning by Pine-apples.— Toxic symptoms fol- 

 lowing upon the eating of pine-apples are reported from the 

 hospital at Hanoi. Indo-China, where cases of such poisoning 

 have been admitted. The actual cause of the poisoning is in- 

 volved in mystery. By some it is attributed directly to some 

 constituent of the fruit, while others believe that the poisonous 

 properties have been induced by the fruit having been bitten 

 by some venomous reptile or other animal. The action of the 

 poison is on the nervous system, and results in heart failure, with 

 cyanosis and purple patches on the skin. Serious and even fatal 

 consequences have ensued, collapse following upon coma. As 

 an antidote a hot infusion of pine-apple bark appears to have 

 been successfully employed. 



