Alternately

adv.	1.	In reciprocal succession; succeeding by turns; in alternate order.
	2.	(Math.) By alternation; when, in a proportion, the antecedent term is compared with antecedent, and consequent.

Adv.

1.

alternately - in an alternating sequence or position; "They were deglycerolized by alternately centrifuging and mixing"; "he planted fir and pine trees alternately"