This section is from the book "The Volatile Oils Vol2", by E. Gildemeister. Also available from Amazon: The Volatile Oils.
The oil from the roots of Aristolochia Cletnatitis, L. was prepared by Winckler1) and Frickhinger2). The former obtained 0,4 p. c. from the dry roots. Walz3) distilled the entire plant and obtained a golden-yellow, viscid oil with an acid reaction and a sp. gr. of 0,903.