cardamoms. A poet says:
As if it is a blade made of rasas nujaddad (white lead), good to me
but otherwise no good.
Possibly he has implied a sword gilded with tin. Tin gilded with
silver has a silver foil pasted upon it with gum. In one manuscript nuhas
murassas has been written in place of rasas-i-mufaddad. This would be
more meaningful.137 God knows the best.
Asrub is lead (anuk). In Persian it is known as usrub. It occurs in
"Iraq and Khurasan, whence it is exported to Rome. It is smelted from a
special clay in these parts and is also mined from stones. This is why it is
base and cheap, but it is held in great esteem in the East where there is
no mine of the metal, and is imported from other cities.
Yahya bin Masaway has said it is ibar. Medicines are made from it
and its collyria enjoy reputation. Shajari Tahir says: "It is known as ibar
and ubar in Syriac." When the name is transcribed in Arabic, the ba' in
the name is replaced by Arabic fa'. Muhammad bin Abi Yusuf says it is
with ba and alif marked with fath, without the maddah sign. He has
offered the hemistich quoted below in support of his philological claim:
Gold is (being) sold in place of lead.
The weight of a rod of lead is 50 ratls. With the axis of gold as the
standard, its weight comes to 60-1/8. Thawfarastus138 in his Masa'il alTabi'yah (The Problems of Physics) says:
If a vessel is filled with molten lead, which is subsequently filled with
gold and silver, the weight of lead would be found to be heavier.
I cannot accept the correctness of this statement, as, according to the
v/eights I have given earlier, this cannot be so. If this statement is made
v/ith regard to the molten states of the three metals, it would be correct
about silver but wrong with respect to gold.
He has made this statement as the molten lead would become roundish and a little air would be able to press between the interstices. When
molten gold and silver are poured into the vessel, the volume of the air
would decrease and the vessel will not fill; there would, therefore, be
considerable space for the air. if so, he should have put the condition
that the neck of the vessel should have been narrow. Even if the vessel is
supposed to have two necks — one for pouring the metal and the other
to serve as the outlet for the air — and is heated so that the metals solidify in the vessel, he would be wrong. Lead has little silver — a fact which
can be verified on calcining it.
A statement is ascribed to Ibn al-'Amid that, when he extracted silver
from lead, it came to ten dirhams, while he spent ten dirhams upon it.