Sir Walter Ralegh - help

[MyUtopia]

Hi everybody, I'm an Italian student in English literature. I really would like to try to give an italian translation to sir walter ralegh's wonderful poems, but I have some difficulties in catching the exact meaning of this stanza, which is from "Nature, that wash'd her hands in milk". I really hope you could help somehow.

Nature, that wash'd her hands in milk
And had forgot to dry them,
Instead of earth, took snow and silk,
At Love's request, to try them
If she a mistress could compose
To please Love's fancy out of those.

This is the first stanza, I obviously get the sense and the general meaning of the lines, but I can't understand whom "them" (in "to try them") is referred to. To nature's hands? To snow and silk?? And I have the same problem with the pronoun "those" (in "out of those"). Thank you so much in advance to all of you.
Ciao!

[Albion]

Sir Walter's poetry was hitherto unknown to me but:

Love requested nature, who had washed her hands in milk and forgotten to dry them, to create a mistress out of snow and silk in order to please her (ie love's) fancy.

to try them ie snow and silk
out of those ie snow and silk

[MyUtopia]

Thanks a lot, it's been very helpful!