First you need to find a scroll of identification:
1) Sin city
2) New Barter Ground
3) Farm locations

Buying scrolls of identify 1

https://pp.vk.me/c623422/v623422951/40477/x_pLNQDCdjI.jpg

Buying scrolls of identify 2

https://pp.vk.me/c623422/v623422951/4047f/Ra_pESg-3TQ.jpg

After that:
1) insert the scroll in the slot for scrolls
2) put thing in slot 2
3) click on the (book)
4) in the window that appears, click on the Identify!
And all thing identified!
https://pp.vk.me/c623422/v623422951/40488/3nOGA3mQdk8.jpg