If the herbage or flower you want to cast is delicate and fine, tin must exceed lead in your mixture; on the contrary, if it the flower or herbage is thick, you must add into your mixture more lead than tin. For a fine thing, add one part of tin for four parts of lead. Your mold must not be too hot, so you can hold it with your hand when you cast. Your alloyed tin must be very hot and almost red for casting, and that way it will enter all the small parts of the mold. Otherwise, your tin will cool down before reaching the thin parts of your herbage. Do not forget to mix a little bismuth in your mixture; that way, your tin will run better and be firmer.
at left top margin of folio 115v
With your lead allied with tin, or tin allied with lead, you can add a very little quantity of bismuth and it will look silvery. But do not put too much, because if hardens the matter and makes it sour, and if your work on fine things —— like legs and similar things —— it will not cast properly.