An exhaustive series of experiments have been carried out at 

 different times, and under varying conditions, w ith the apparatus, 

 using different fuels in the furnace, e.g., coal, coke, and charcoal, 

 or mixtures of these. 



The chief difficulty, which it is hoped may eventually be 

 surmounted, is the regulation of the requisite temperature in the 

 retorts. A sufficiently high temperature must first be obtained 

 to start the reaction, and secondly this temperature must not be 

 greatly exceeded otherwise the carbon bisulphide will be again 

 broken down. Till the present time, both in the original 

 apparatus and in modified forms of this apparatus, the necessary 

 conditions have not been obtained. 



Experiments are still being carried on, and recently an 

 earthenware retort has been tried, as the corrosive action of the 

 sulphur on the iron retort at the elevated temperature used, was 

 round to disintegrate the latter completely in a very short time. 



In the event of this small field retort and furnace being 

 unsuccessful, either a large plant will have to be erected for the 

 Production of this insecticide, on the same principle as those at 

 present in vogue, or the liquid will have to be imported for 

 agricultural purposes ; the latter method has many disadvantages 

 jnd there is no reason why the compound should not be success- 

 rally manufactured here if necessary precautions are taken. 



Effects of Arsenical and Sulphur Fumes from Tin- 

 Roasting Furnaces on Vegetation. 



• The effects of arsenious acid on the root or stems of a plant 

 'mmersed in a solution of the acid is said to be similar to that of 

 not water, the foliage turns a brown colour and rapidly withers. 

 Hants grown in earth containing arsenic are said to only take up 

 J ute quantities, and the toxic effect is negligible. The principal 

 Sati arSenical fumes from factories on vegetation is that ot 



In order to demonstrate definitely the effects of the noxious 

 chiefly arsenious acid and sulphur dioxide, in the fumes 

 C th ,V in casting furnaces in these States, a small model 

 r na ce (about quarter of the original size) has been erected by 

 £ Dl ^tor of Agriculture in the grounds of the Institute for 

 W d Rese ^ch, and a long atap shed, open at both ends and 

 °£rtation° n l0ng P ° leS ' ^ ^ eXpen 



ade tin ores containing high 

 :al iron pyrites) are to be roasted, 



