IOWA ACADEMY OP SCIENCE 
155 
investigations at the result that all crystalline substances can also exist in a 
noncrystalline or amorphous form and that these two forms are so distinct from 
each other that they must be regarded as definite allotropic modifications. 
Further he showed that in the pure ductile metals the crystalline state is 
actually the soft state, while the hardened metal is a complex structure built up 
Of crystalline and noncrystalline substance. During the drawing some of the 
crystals pass into the amorphous state and during the sudden congealing after 
the removal of the pressure the crystals are bound into a rigid mass irrespective 
of any orientation. When this mass is heated to a temperature far below the 
melting point of the metal recrystallization of the amorphous part takes place 
and the wire becomes soft. 
This theory explains many peculiarities of hard drawn wire. Gray and Mees 
and more recently Wassmuth have shown that the density of wires drawn under 
great pressure is smaller than before drawing. Applying this theory to the re- 
sults discussed in this paper, we have to assume that the amorphous state has a 
smaller rigidity than the crystalline state and we must expect a larger logarith- 
mic decrement in amorphous solids. If the elastic after effect is due to a slipping 
•of crystals with respect to each other the after effect should become smaller 
when the crystals are closely surrounded by the amorphous mass. 
To test these conclusions experiments were made with fused quartz and car- 
bon filaments, both amorphous substances. The quartz fibre was very thin and 
480 mm. long. The elastic after effect was very small, the time of vibration 
very constant and no decrease of the decrement with amplitude could be ob- 
served. The decrement was 0.000572, a value twice as large as was obtained 
with much thicker metallic wires. 
The thin carbon filament, 20 cm. long, had the very large decrement of 
0.00548, the amplitude decreasing in 176 swings to one-tenth of' its original 
value. But the decrement remained perfectly constant. 
A similar effect to that of hardening by drawing can be produced in a 
palladium wire if hydrogen is deposited upon it by electrolysis. With a palla- 
dium wire this treatment produced an increase of the decrement from 0.0006 to 
0.003, while the period was decreased from 7.954 sec. to 7.778 sec. The absorp- 
tion of hydrogen is considered as a solution of hydrogen in the metal and it is 
quite reasonable to suppose that the crystalline structure of the wire is greatly 
impaired by such a treatment. With the 25 per cent platinum-iridium wire men- 
tioned above, annealing reduced the logarithmic decrement from 0.00124 to 
0.000327 without showing any other noteworthy effects. 
The same treatment failed, however, completely with the 40 per cent plat- 
inum-iridium wire. Thinking that perhaps the temperature of the Bunsen 
burner was too low to raise the wire to the point of recrystallization, I sent 
through the wire, not under tension, an electric current sufficiently large to 
heat it to bright yellow heat. The point of recrystallization was undoubtedly 
reached and the crystals must have arranged themselves in any imaginable way; 
for placing the wire again in the torsion apparatus I was unable to get aTny zero 
point at all, though the wire was kept in continuous vibration for two days in 
the hope to have the crystals fall in line. They absolutely refused to do so and 
during each attempt of making a measurement the zero point shifted at least 
10 cm. over the scale in the direction in which the torsion had first been applied. 
