BAILEY. | Chemistry of Gypsum. 141 
PLASTER OF PARIS FROM FRANCE. 
Analysis by M. Durand-Claye.®? 
Silica and insoluble residue’ ::.;................ 4.9 1.4 0.6 4.0 
[ora gyal alluraawiayyian Oba. Job osvscdossoooduoc i fD) i) 0.8 1.4 
IMEIOMeSiIMECAR DON alee mrt ert ais ilo 5.05 2.3 Boll 5.05 
Calcium yearbonatereeee eee See ac ar ae ea OR 9.9 2.4 14.1 
Calciumysulphavecsrese ete eer sae eer 70.9 79.05 87.7 71.6 
NYYEN TEND 9 Sd ly A MET OIG ie Oe 6.45 58d 5.8 3.85 
ANALYSIS OF BOILER INCRUSTATIONS. 
A good illustration of the fact that a hydrate similar to the 
calcined plaster may be formed from evaporation of sea water 
is found in the analysis of the boiler incrustation of an Atlantic 
steamer using sea water. Calculating the amount of each con- 
stituent in per cent. the results were : 
Calcium carbonate dS BS SISee is to cio HG REE A AROSE SEO SReTER 0.3 
LronvoxiG en (Leni C) Meee meter lula vine ra eave AA en ges 2.0 
Water teeiin. iy Sigh Clue spy Gaokbue chee HS OS OR eR tA ee a OR ae 5.8 
Cal crumaysuilp hate meyers ca sass sea layne a eye ca nectar beg Soles S19 
AOL. 8 o OGG Skid SCD GROG OOTY SAI eae ae Ree RR ear 100 
This compares closely with the theoretical amount as regards 
water and calcium sulphate. 
Some specimens that have been analyzed from foreign lo- 
calities have the following composition : 
GYPSUM FROM FOREIGN LOCALITIES. 
/ Wienrode, | Osterode, Albay 
by Jungst. |by Hampe, (Philippines), 
SilicaranGsnsolulolemesidiienen eee eee 2.80 0.15 6.43 
Irom ayavel aykohooianbhan ODaGleSs oo nc oooulsbosoeobosuee ORGOR| ener. 0.64 
@aleimmypoxidennery er eee. wees oc 31.87 32.44 29.41 
Sulphurichanhydrid opener eres ian 45.76 46.61 44.19 
NAIL G Darran terre cnn rh ett Mes a SED IRL A lo 19.90 20.74 20.18 
ERO GELIS Speen ae Seer Pas a NI cuir oly 100.93 99 . 94 100.85 
59. Dictionary of Applied Chemistry, Thorpe, Vol. I, page 473. 
