IV. Of the nature of silk as it is made in Piedmont

Silk, which is the Spittle of a Worm, hath its good or bad Quality from the Nourishment the Worm receives either from a good or bad Leaf; Therefore the chief Dependance is on a happy Spring, proving both sweet and pleasant; exempt from too much Rain, which commonly rot the Leaves; from Southerly Winds, which burst the Worms; and from strong Northerly Winds, whose piercing cold spoils the Leaf, giving it an ill Quality.