174 
Proceedings of the Royal Irish Academij, 
Throngli the top of this boiler passed what may be described as a 
kindofBeals' ''filter." It consisted of a glass tube, bent at right 
angles, one of the ends of this tube being moulded into a bell-shaped 
mouth, which mouth was tied over with a piece of Swedish filtering 
paper, and over this again a piece of muslin, which might be also 
placed upon the other side, if great pressure were going to be used. 
By this arrangement, although the orifice presented a perfect filtering 
medium, it would stand a considerable amount of pressure. This end 
was submerged about half way into the boiler, which was filled with 
pure lime water, procured as in the previous experiment. The other 
end of the tube was provided with a glass stop-cock. The stop-cock 
was closed, and the lime water rapidly brought to the boil. On 
allowing the valve to exert a slight pressure in the interior, and open- 
ing the stop-cock slightly, the lime water slowly flowed out, the 
pressure in the interior being just sufiicient to force the lime water 
through the bibulous paper, and up the capillary tube. The thermo- 
meter would occasionally go up a degree, but this was at once remedied, 
by opening the valve. When a sufiicient quantity of water had been 
collected in this manner, the amount of lime was estimated as in the 
previous experiment. 
In two determinations 3002 grains consumed 8 degrees of the vol. 
Ca"0 
solution 8- =2-24 grains lime present, or 1 in 1340. 
Experiment IV. — Determination of the Solubility at 109** C. : — 
This experiment was performed in exactly a similar manner to 
the previous one, except that the valve was so placed that it blew off 
at a pressure corresponding to a temperature of 109° C. 3000 grains, 
obtained in this manner, consumed 6 degrees of the volumetric solu- 
CaC 
tion of acid ; 6* -——-== 1-68 grains of lime in solution. 
These results may be tabulated as follows : — 
One Part of Water at — Takes up of Ca" 0— 
15f c, 
109- ttW 
and so on, until a point would be reached at which lime would practi- 
cally be insoluble. 
* Dalton's experiment iipon this subject are in kis "New System of Chemical 
Philosophy," Part 2 ; Manchester: 1870. They are as follows :—" When water 
of 60° is duly agitated with hydrate of lime, it clears slowly, but a quantity of lime 
water may soon be passed through a filter of blotting-paper, when it becomes clear 
and fit for use. I found 7000 grains of this water required 75 grains of test sul- 
phuric acid for its saturation. Consequently, it contained 9 grains of lime. If a 
quantity of this, saturated with water mixed with hydrate of lime, be warmed to 
