222 



Field Columbian Museum — -Geology, Vol. i. 



table following gives the measurements by which these forms were 

 identified, together with measurements of the other forms noted. 

 The calculated values given with them are deduced from Scheieb's 

 ratios as quoted by Dana.* 



No. of 

 Measurements. 



Limits. 



c : s=ool : 946 .... 



g: $=201:946 



a: s— 100: 946 



d : $=011:946 



b' :s—oio: 946 



c : £=001: Tf.0.12. 

 A : a' =11.0.12: 100. 

 a : g=ioo :20i . . . 

 g : £=201 :ooi . . . 

 b' :d=olo : oil. . . 



d:c=oil : 001 



c : b=ooi : 010. . . 

 a: b=ioo :oio . . . 

 b.a'=oio : Too. . . . 



79° 48' — 80° 42' 

 52 36'— 55 34' 



11° 47' — 12° 27' 



34° 36'— 35° 9' 

 48 27' — 50 40' 

 46° 25'— 46° 30' 

 82 4 8"-84° 35' 

 8o° -86° 33' 

 97 25' — 100° 



Observed. 

 34° 



13° 23' 

 19° 47' 

 45° 20' 

 84° 30' 

 8o° 26' 

 52° 25' 



12° 



34° 36' 

 48° 34' 

 46° 30' 

 82 50' 



82 30' 



97° 25' 



The crystal faces were found in general 

 to be fairly flat and bright, except the clino- 

 pinacoids, which were always vertically stri- 

 ated, so that no very satisfactory measure- 

 ments could be made from them. The usual 

 habit and development of the crystals is illus- 

 trated in Fig. 1. Fig. 2 shows a completed 

 crystal giving the new forms, k (11. 0.12) and 

 s (946) in their relative development. 



Calculated. 

 34° 10' 



13° 30' 

 19 48' 

 45° 21' 

 84° 33' 

 8o° 9' 



53° 9#' 



12 5' 



34° 36K' 

 49° 23' 

 47° 22' 

 83° 15' 

 82° 35' 

 97° 25' 



a c / 

 '/ ■ 1 



\ 9 



—1, 6 



a 1 



Fig. 1— Inesite. 



Fig. 2— Inesite. 



An analysis of the mineral was made by the writer. For this 

 purpose about two grams were laboriously separated from the calcite 

 in which it was largely embedded. Experiments were first made 

 upon the temperature at which water was driven off in order to deter- 

 mine, if possible, the nature of its existence in the mineral. About a 

 gram of the finely powdered mineral was heated at successively 

 increasing temperatures until practically constant weight was 



♦Dana's Mineralogy, p. s6s. 



