RICHARDS AND ROWE. — SPECIFIC HEATS OF LIQUIDS. 187 



tacle (F) tlirough a burette, and the piece was suspended from its 

 proper place in the lid of the submarine vessel below the cap (E). 

 Extremely accurate determination of the amount of alkali was not 

 necessary, for its concentration was such that its own heat of dilution 

 was approximately that required to raise itself through the tempera- 

 ture range of an experiment. Any excess therefore was self-heating 

 and made no appreciable effect on the rise of temperature caused by 

 neutralization; but nevertheless careful measurement with a burette 

 insured the use of very nearly the same quantity' in each case. There 

 was always the same slight excess over and above the amount needed 

 to neutralize the acid. 



The standard acid, the one reagent whose quantity needed accurate 

 determination, was next weighed into the wide mouthed platinum 

 bottle (D). It was then rapidly brought to the desired temperature 

 and made fast by a water tight rubber collar to its open cap (E), 

 which had been previously suspended beneath from the cover of 

 the submarine vessel above the receptacle for the alkali, as already 

 stated. The calorimeter-stirrer was then added through its proper 

 holes in the lid, and the whole system attached to this lid (or cover) 

 was transferred to the submarine vessel, the bottle being immersed 

 in the calorimeter. After the screws had secured the lid in place 

 and made it water-tight with the help of the large rubber washer, the 

 level of the outer bath was raised by adding dilute caustic soda, and 

 the various stirrers were set in motion. A very few minutes sufficed 

 to establish thermal homogeneity. The addition of a little ice-water 

 or acid permitted the ready regulation of the bath temperature. 

 When the temperature of the system had become uniform, the inner 

 thermometer was carefully read and the result was recorded as the 

 initial temperature of the experiment. The calorimeter-stirrer, 

 operating at a rate of 45 strokes per minute was found to produce 

 practically no mechanical heat in the time of the experiment, and the 

 effect of outside air which might be pumped in through the openings 

 was also found to be negligible during this time, unless the tempera- 

 ture of the room was widely divergent. Hence no corrections had to 

 be applied for these otherwise disturbing side-effects. 



All being ready, the rubber stopper was forced out of the receptacle 

 containing the alkali, and the concentrated caustic soda solution was 

 allowed to flow into the standard acid. At the expiration of three 

 minutes the receptacle, still rotating, was lowered almost to the bottom 

 of the bottle, thus permitting a free mixing of the acid and alkali, which 

 was hastened by raising and lowering the receptacle at appropriate 



