Removing two hard drives in a single enclosure.

Back in 2007 I bought one of the first terabyte hard drives. Later to find out it was actually 2 500gb hard drives sandwich together in a hard drive enclosure. I believe it only has the ability to transfer over ethernet no USB or firewire ports on the actual hard drive. Needless to say it was an awful product that gave me nothing but issues. I took the hard drives out of the enclosure because I would love to be able to retrieve any data that's still on the drives. I'm not sure if the drives are even alive anymore or at a point where data recovery is still possible. I attempted to separately plug in each Drive-In a 3.0 USB adapter but I wasn't getting anything. My question is do I need to daisy chain both hard drives together in order to access any actual data that may be on there? Both drives were Daisy chained together before taking them out of the hard drive enclosure.