456 Sir G. C. Haughton oti the Coinmon Nature of 



The prism was raised by the magnet from 30° to 60°, but 

 the sreen glass, to which the magnetic needle attached itself 

 with great difficult}-, seemed to acquire repulsive rather than 

 attractive powers by the same means. This was a specimen 

 of fancy glass, of an apple-green colour, and cut to represent 

 the calyx of a flower. 1 am ignorant as to what metal it owetl 

 its colour. It will be seen hereafter that the prism, which 

 was of English fabric, exhibited an extraordinary affinity for 

 all the metals, as well as for flint glass. Tiie common green 

 glass employed for wine bottles, and crown glass, notwith- 

 standing the iron they contain, exhibited no striking attraction 

 for the magnetic needle, which can be easily accounted for by 

 remembering that the iron is in intimate combination with 

 other bodies, and having its affinity employed, simulates 

 neutralit}'. 



The particular kind of porcelain used by dentists has very 

 little attraction for the magnetic needle, and in other respects 

 exceeds even the glasses in its affinity for non-ferruginous 

 metals and gelatinous bodies. It and stone-ware are much 

 alike. 



The crystals of various kinds in this class, with the excep- 

 tion of protosulphate of iron, exhibit very low magnetic in- 

 tensities for the needle, and confirm what I have said about 

 the common glasses. Carbonate of iron, it will be seen, has 

 but little affinity for the magnet. Iceland spar is as difficult 

 and capricious as flint in its attraction for the needle, but is 

 remarkable in its affinity for non-ferruginous bodies. Talc 

 has but little attraction for the magnet and zinc, but it is 

 otherwise with iron and gold. It was not tried with other 

 bodies. The specimen, which was remarkably thin, came 

 from Delhi. The other substances were not measured, but 

 the needle connected itself with them. Crystallized tin failed 

 with the magnetic needle, but rose to 90° after contact with 

 the bar-magnet. 



5th Class. 



Pearl 90+ 



Nacre 90x X 



Ivory (new) 90-)- 



Do. (old) 58 



Enamel (human 



tooth). 



Uoiie(niackerers) 90 



AMialehone 90 



Tortoise-shell ... 85 



Horn (buffalo's).. 90 



Horn (cow's) 85 



Do. (chamois') 90 



Leather. 



Black seal's skin ... 62 



Quill. 



Pig's bristle. 



Human nail. 



Human hair (brown, 



male's) 90 



Do. (female's, young) 80 



Human hair (female's, 



young, 2n(l specimen) 76 

 Do. (do. 3rd specimen) 82 

 Do. (female's, old) ... 90 -|- 

 Do. (gray, male's) ... 90 -|- 

 Do. (do. 'female's) ... 90-j- 



Do. (beard, gr.iy) 90 



Hare hair (grav) 90 



Do. (black) ...' 90 



Cat's wliibker 90x 



