656 Transactions. — Chemistry and Physics. 



while cold water circulates through the lower. The liquid 

 to be experimented ou fills the cylinder, and finds itself, there- 

 fore, between the two capsules. After a time, depending on 

 the thermometric conductivity of the liquid, a state of con- 

 stant flow is set up. To compare two liquids the time to 

 reach the constant state for each is measured, 8.nd the ther- 

 mometric conductivities are then inversely as the times. 



Naturally the apparatus lays no claim to scientific 

 accuracy ; it enables one, however, quickly, and with fair 

 success, to demonstrate the relative conductivities of any two 

 liquids. If the stem of the open-air thermometer is of fairly 

 true bore, the relation between the times necessary for any 

 required rise of temperature, or between the times for suc- 

 cessive equal increments, also allows of easy demonstration. 



Art, LII. — On the Distillation Products of the Blackball 



Coal. 



By Dr. W. P. Evans. 



[Read before the Philosophical Institute of Canterbury, 2nd November, 



1898.] 



Part IV. 



The following experiment was caiTied out with the object 

 of testing the results re distribution of sulphur arrived at in 

 Part I.* :— 



Tfjrough d Si d 

 to /fspintor 



The coal was placed in a bent bulb-tube of hard glass (a), 

 connected in series with a Wiirtz flask (6), a U-tube (c) filled 

 with dry cotton-wool, three small wash-bottles (cZj, d^, d^) 

 containing an ammoniacal silver nitrate solution, and an 

 aspirator. The aspirator was arranged so as to just counter- 

 balance the liquid columns in the wash-bottles. The tube 

 containing the coal was hooded with asbestos millboard, and 

 very gradually brought up to a full red heat. At the end of 



Trans. N.Z. Inst., vol. xxx., p. 489. 



