Agate— Archaeology and Folk-lore 
31 
Another theory was based on the name for agate, 
ma-nao, which means literally "horse's-brain." In 
writing the two characters, each is usually preceded by 
the classifier "jewel" or "precious stone." The signifi- 
cance "horse's brain" is regarded by most Chinese 
authors as the origin of the word, and may have been 
elicited by a certain outward resemblance of the veins 
and striation in agate with the brain of a horse. Hence 
a popular notion arose that agate beads were spit out 
of the mouths of horses. 
For the purpose of testing agate the following 
recipe is given : "Rub it with a piece of wood ; if it 
does not become heated, it is genuine; if it will be 
heated, it is not genuine." This test is based on the 
notion that the nature of agate is cold and that its 
coldness is unchangeable. The Chinese formula is 
practically identical with what Pliny ascribes to Per- 
sia: there the efficacy of an agate was determined by 
throwing it into a cauldron of boiling water and turn- 
ing the water cold. It may be that the Chinese derived 
this idea from Persia. 
In the first centuries of our era the Chinese be- 
came acquainted with the fact that agate and many 
other valuable stones were abundant in the Near East. 
As numerous articles were then traded from the Hel- 
lenistic Orient to India and China, while Chinese silk 
found its way to the West, it is very probable that 
agate was included among the export products of 
western Asia. 
It is even possible that agate first became known 
to the ancient Chinese as an importation from abroad, 
for it is not mentioned in the literature of pre- 
Christian times, and the earlier authors inform us that 
it came from western countries, from the countries in 
the south-west, or from the western and southern bar- 
barians. In one source it is even stated that it was a 
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