Fes, 1900. NEw MINERAL OCCURRENCES—FARRINGTON, 223 
obtained at each. The following are the percentages of loss obtained: 
At 110°, 3.88%; at 240°, 1.94%; at 310°, 0.10%; at faint redness, 
1.00%; total, 6.92%. Of the above amount, 5.99% was taken up 
again by the mineral on exposure to ordinary air. This amount may, 
therefore, be regarded as water of crystallization. On continuous 
heating at faint redness, the mineral turned dark and showed a gain 
in weight doubtless from oxidation of manganous compounds. It 
was evident, therefore, that water could not be correctly determined 
by loss upon ignition. 
A direct determination was made, therefore, upon a separate 
portion by Penfield’s method,* a blast lamp being used for the final 
heating. This determination gave 8.20% of water. It could be dis- 
tinctly seen on application of the higher heat of the blast lamp that 
more water was given off at the high temperature, showing beyond 
question that some of the water was present as water of constitution. 
If the percentage of water taken upon exposure to air, 5.99%, be 
regarded as water of crystallization, then the remainder, 2.21%, may 
be considered to denote the percentage of combined water. This 
agrees well likewise with Barwald’s observations, he having found 
1.97% of water given off above 300°. It is evident from the above 
experiments also that determination of water as loss upon ignition 
would certainly give too low a result. This may account for the low 
percentage, 7.17%, obtained by Flink. 
The remainder of the analysis was performed by the methods 
commonly employed for the analysis of silicates. A sodium carbon- 
ate fusion was made, the bases separated from silica by solution with 
hydrochloric acid, iron precipitated by ammonia, manganese by bro- 
mine and calcium by ammonium oxalate. Results of the analysis 
with ratios are as follows: 
———_—-- Ratio——_ 


Ma da. Su ctws a dus ® ere 44.80 48 748 1.64 
EY Bement vas eles 36.53 517 | 
CIR Re ie sha Wane ornb 2.48 034 / 699 r53 
RACES nis gece aide «Sra 8.24 148 
OED AOR hes Babe-at ag ew hee tk 
RAMOMUTUSE fasta wne'aeieise 5.99 336} 456 
PPEG) CONSE S| succor Ze2t 120 | 
100.34 
Sp. Gr. (det. by Thoulet’s solution)=2.965. 
The ratio of SiO,: RO : H,O is thus nearly 1.5: 1.5 : 1. Consid- 
ering the ratio of water of crystallization to water of constitution 
= 3:1, and of Mn: Ca= 4:1, the formula can be expressed as 
*Amer. Jour. Sci., 3rd Ser., Vol. 48, p. 30. 
