Dr. Pearson's Observations 
44 ^ 
been broken off. I have already described this instrument in 
the account of the brass arms. 
§ 2. Chemical Properties. 
1. The Sword , fig. 1. Tab. XV. 
( a ) Being filed and polished, it was of the colour of steel. 
The blade was bent considerably before it was broken ; and 
could not be broken without considerable force. — Compara- 
tively with soft steel, or malleable iron, it possessed little mal- 
leability. — Under the hammer, file, and drill, it felt as hard as 
hardened steel. The snipt edges were hard, and strong enough 
to saw asunder the celts, described in this paper. Its fractured 
surfaces showed a silvery kind of open grain, like steel which has 
been hardened by plunging it, when white hot, in cold water. 
The pommel and guard were much more malleable, and 
much less hard than the blade. 
( b ) The blade, when red hot, was malleable, but much less 
so than our common steel. On cooling gradually it became 
less hard than before ; but it was not so soft as our common 
annealed, or distempered steel. By plunging the distempered 
piece of the blade, when white hot, in cold water, it was re- 
stored to its original hardness. By plunging the pommel and 
guard when white hot in cold water, they were rendered much 
harder ; and by again igniting them, and letting them part 
with their fire gradually, they became as soft as they were ori- 
ginally. 
(r) The specific gravity of the middle part of the blade, 
after filing off the coating, was 7,47b. 
( d ) The dissolution of 300 grains of the blade in sulphuric 
acid and water, yielded nearly the same quantity of hydrogen 
