1889.] Temperature and Specific Inductive Capacity. 357 



lis inactivity towards dulcite is particularly interesting, and fur- 

 nishes another instance of the selective power of micro-organisms 

 towards the most closely allied isomeric bodies. Remembering the 

 relationship of dnlcite to galactose and of galactose to milk-sngar 

 (galactose is converted into dulcite by nascent hydrogen, and milk- 

 sugar is converted into galactose and dextrose by the action of dilute 

 acids), it is to be anticipated that in the fermentation which this 

 bacillus induces in milk-sugar, the decomposition is limited to the 

 dextrose portion of the milk-sugar molecule. In the action of this 

 bacillus on starch, the latter is in the first instance dissolved, doubt- 

 less through the agency of a diastatic ferment, to which the organism 

 gives rise, as well as to the peptonising one which brings about the 

 liquefaction of the gelatine already referred to. A tube containing 

 starch-liquid, which had been fermented by the bacillus, gave no blue 

 coloration with iodine, clearly showing that the whole of the starch 

 had undergone transformation into other products. 



(8.) In view of the characteristic products — ethyl alcohol and acetic 

 acid — to which this organism gives rise, we propose for it the name 

 of Bacillus ethaceticus. 



XL " On the Effect of Temperature on the Specific Inductive 

 Capacity of a Dielectric." By W. CasSIE, M.A. Commu- 

 nicated by Professor J. J. Thomson, F.R.S. Received 

 May 24, 1889. 



(Abstract.) 



The variation with temperature of specific inductive capacity was 

 measured in different ways for solids and liquids. 



In the case of solids a condenser was made with thin sheets of the 

 dielectric in question, and the capacity measured at different tempe- 

 ratures. The condenser was suspended in an air-bath by wires pass- 

 ing through the top to an insulated support outside. This support 

 was several feet above the bath, so that it was never heated, and its 

 insulation was independent of the temperature of the condenser. The 

 capacity was measured by Professor J. J. Thomson's method,* and 

 conduction or absorption in the condenser allowed for by varying the 

 time of charge and discharge. The rate of increase per degree centi- 

 grade of the specific inductive capacity was found to be for — 



Mica between 11° and 110° 0'0003 



Ebonite „ 13 „ 63 .... 0-0004 



Glass „ 17 „ 60 .... 0-0012 



Another specimen of „ „ 13 ,, 60 .... 0*002 



* ' Phil. Trans.,' 1883. 



