the Elements Carbon, Boron, and Silicon. 



277 



grms. was placed in the inner of two long test-tubes, which were 

 then sunk to the neck in the ice of an ice-calorimeter : a stopper 

 of cotton-wool prevented the outer air from coming into contact 

 with the graphite. As the graphite was gradually cooled down 

 the motion of the mercury thread was carefully noted, with the 

 result that the forward movement was equal toOll division per 

 minute. When the temperature of the graphite was 0° it was 

 quickly removed and placed in the receiving-vessel of the calori- 

 meter, and the movement of the mercury thread again carefully 

 noted. The forward movement was exactly the same as that 

 noticed before the introduction of the graphite ; hence it follows 

 that there is not the smallest evolution of heat from the contact 

 of graphite with water. Another experiment proved that the 

 amount of gas absorbed by 3 grms. of lamellar graphite did not 

 alter the weight of the mass so much as one milligramme. 



The following experiments were carried out with a piece of 

 very pure lamellar graphite from Ceylon. The percentage of 

 ash in this sample of graphite was 0*38 ; the numbers deduced 

 for the specific heat will therefore hold good for absolutely pure 

 graphite within 1 or 2 units in the fourth decimal place. I did 

 not determine the hydrogen which was possibly present, as Kopp 

 has found that the amount of this element in Ceylon graphite is 

 exceedingly small, varying from *06 to *17 per cent. 



a. Experiments carried on at ordinary Temperatures with the help 

 of the Ice-calorimeter, 



First Series. 

 N = 10-24. 



G. 



T. 



N. 



W. 



Co-t. 



3718 

 3-718 

 3-718 



-79-35 

 -79-20 

 -79-30 



3660 

 367-2 

 370-2 



-3574 

 -35-87 

 -3517 



01212 

 01218 

 1227 



3-718 



-79-28 



367-8 



-35-93 



01219 



W™ 9 . 3 =:9-G64. 



Second Series. 

 N = 10-24. 



3-718 

 3718 

 3-718 



-21-52 

 -2120 

 -21-35 



1170 

 1167 

 1180 



-11-42 

 -11-40 

 -11-52 



01428 

 01447 

 01451 



3-718 



-2136 



117 2 



-11-44 



01442 





W -21-4= 3 " 076 - 





