EXPLANATION OF PLATE XXXVI 

 Fig. 1. Simple microscopic crystals of praseooctaminosulfate. Forms 



hemidomes 



orthopinakoid produce the pseudohexagonal outline; e is a partly developed form; / a combination of forms; 

 d and h the so-called paddle form; h the staff-type overwhelmingly prismatic; g the book-type. 



Fig. 2. Bizarre twin forms: a, nearly rectangular twin producing the block-type; 6, the butterfly type; 

 c, the bug type; d, the tongs type; e, /, g f incomplete twins. 



Fig. 3. a, 6, the chi or saw-buck type; c, the angle-templet type; ff, the tongs type; d, the burr-type; 



e, the digitate-type; h, g, the grass-type. 



Fig. 4. Microscopic figure prepared from Mohawkite. a h a Xy a 2 , a 3 , a 4 , a 6 , a* are blue, monoclinic com- 

 binations of cupritetraminosulfate; 6, b h b 2) 63, green, isometric combinations of nicolotetramino chlorid; 

 cccc . . ., olive-green monoclinic combinations of praseo-cobaltioctaminosulfate. 



Fig. 5. Glass-tube with a fascicle a of copper wire tied by two asbestos cords, 6, c; in sectional view. 



Fig. 6. The glass-tube after the action, a b are the blank spaces which had been protected by the 

 asbestos. Between these two the glass is deeply stained with the ruby color, forward of a less deeply and 



rearward of b least stained. 



Fig. 7. The mixed effect of ruby stain and superficially attached copper-spangles. The dots, repre- 

 senting spangles are not of the same color in reality, the spangles are of the faint pink color as the wire m 



Fig. 5. Exp. X. 



Fig. 8. Faint and partial staining as produced in Exp. 



Fig. 9. Wire-fascicle in outline. Very broad blank ri 

 a strong ruby stain projecting forward of wires, at b ruby stain-band less strongly marked, at c a iaint ip 



of copper-spangles. Exp. XIV. m m . A , . g , * _ flm j 



Fig. 10. Magnificent development of ruby stain between the cords, a fajnt stain forward 01 a ana 



two rings of spangles rearward of 6. Exp. XXIII. . , w t ^^ 



Fig. 11. Result of Exp. XXXVI. a, a purple colored ring surrounded by ruby stain, 6, bianj gjw 

 protected by asbestos; c uniformly mixed ruby stain and spangle-copper; d, blank glass; e impure u^ j 

 stain and spangles; /, very dark ruby stain surrounded by aureole; g, blank glass; A, a gray ring, , 

 gray ring; k, a bright yellow ring not given in color . 



XI 



cords. At 



