178 
water and ice, or ice and salt, depending on the temperatures required in 
the tank T,. 
The water used in this experiment was first distilled in the usual 
copper still, then with potassium permanganate in glass, then twice again 
in glass. Just before using the water was boiled for fifteen minutes to 
drive off absorbed gases, and then rapidly cooled by placing the flask in 
ice water. The water was siphoned from the flask through a glass siphon 
with a cock which permitted the flow to be adjusted at will. Before open- 
ing the cock the water in the flask was each time brought to approxi- 
mately the temperature indicated by the thermometer t, It was then 
passed through the tube Gi (which had a length of some fifty centimeters 
inside the oil) into the dish Di. Sometimes the measurements were made 
with the water in D: at rest, sometimes with the water flowing very 
slowly from the tube, this giving a fresh surface as free as possible from 
absorbed gases or contamination of any kind. 
The author feels sure of all his data except bis temperature measure- 
ments. The thermometers used were bought for high grade instruments. 
It was the intention to calibrate them at the conclusion of the experiment. 
By accident they were placed with some others of the same kind and so 
could not be identified. 
The results obtained in this investigation are given in the following 
table and are plotted in Fig. 3. 
Temperature Tension in 
of the Water— Dynes per cm. 
07 
esse ais fevereie cys wenge cre nemevais chet cvile) SiSve tunics isp elueiiavs Seve ecegene Ne Oke 74.95 
Rts Gas fra roan ta etarate Veo Ua hy ele tad ty cure seh oiee eran) Pel NOs diaries Shea) 
ICO} (arnt nea Pcie tin ois Se ran Gey De ROR PORTERS oro 73.667 
DU ERis Oveacont st cay eoeeg eal ns Here ct aint heahas dy SN Tal ais he aiscley shu aM soa 73.087 
yen eas RCS ho Chat ac CP ERS eric eee Grate Mot: 72.20 
PAN GT AE Reker Rens Cr a PO oO ER Ry Cree 70.795 
DIGIC CRD ERG CPN On EHO RENEE Oe ENO RO) APHENS SCR FG ota A 39.32 
I ehics Persie ye, serie stare Pekeen ciRt eta oral Se ta We Wiete ia ana Rat 67.36 
DileAir vas evenapon Nels Mes, HaLee comers tot rts vete eM Ribrs hoy aie Kare keke a 67.27 
GAG sichecak cued te ust are ene Read Cec iatc layecegsive ver: Stra taal ieeeet ens 65.50 
Oilracen eens, Shcteca tar sen ener Meer celine: sks tas SAN cat Ie Pee 64.45 
