[ 107 ] 
III. On some of the Properties of Water and of Steam. 
By William Ramsay, Ph.D., F.P.S., and Sydney Young, D.Sc. 
Received November 5,—Read December 10, 1891. 
[Plate 7.] 
The work of which an account is given in the following pages was carried out in the 
winter of 1887-88, and forms a sequel to much of a similar character already pub¬ 
lished by the authors, on methyl, ethyl, and isopropyl alcohols, on ethyl oxide, on 
acetic acid, and on a mixture of alcohol and ether (‘ Phil. Trans.,’ 1886, Part I., 
p. 123; 1887, A., p. 57; 1887, A., p. 313; 1889, A., p. 137; * Chem. Soc. Trans.,’ 
1886, p. 790 ; 1887, p. 755). 
The apparatus with which it was carried out has been fully described in the memoir 
on ether ( loc . cit.). The only important change was in the nature of the glass tubes 
used to contain the liquid under experiment. While, in the case of the alcohols, 
ether, &c., lead glass proved the best material for tubes, it is too easily attacked by 
water. At comparatively low temperatures it becomes etched, and it is impossible to 
take readings. Moreover, the water dissolves a not inconsiderable quantity of 
potassium silicate; tubes of green boiler-gauge glass were, therefore, substituted for 
tubes of lead glass. This glass consists of a silicate of calcium and potassium, con¬ 
taining a trace of ferrous iron (Si0 3 = 71'20 ; CaO=14'99; K 2 0 = 13'19 ; Total, 99’38.) 
They withstand a higher pressure than lead-glass tubes, and they are attacked with 
difficulty. Even after an exposure of several days to liquid water at 280° C., only 
0'7 per cent, of residue remained on evaporating the water. Inasmuch as some of the 
material of the glass is dissolved, however, the water cannot be considered to be 
absolutely pure, but the results may be given as the best attainable with water in 
contact with glass. 
It may be advisable to state here again, that the pressures were read from gauges 
containing dry air, kept at a known temperature by jackets of running water; and 
that they are corrected for deviation from Boyle’s law by help of experiments made 
by Amagat (* Compt. Rend.,’ vol. 99, p. 1153); that the temperatures are those of 
an air-thermometer, and that they were secured by jacketing the tube containing the 
water with the vapours of pure chlorobenzene, bromobenzene, aniline, methyl-salicylate, 
or bromonaphthalene, of which the vapour-pressures corresponding to known tempera- 
P 2 26.4.92 
