Toxygene is a great sample from one the Orb's most under-rated albums, Orblivion. It is a great, quirky dub piece that pretty much defined the Orb's sound around 1997. The CD single was broken into two parts, sold separately. Both are great--although it makes no sense to me why a single had to be sold in two CD's. All the mixes are great. The stand-outs are the EXCELLENT Filia Brazilia version, which stays close to the original Orb version, and Kris Need's Up for a Fortnight which is a fantastic dance mix.
The cds are also worth the purchase price for the remix of Delta MKII and a really nice ambient piece called Rose Tinted, which is sort of a quiet mix of Toxygene and Asylum.