Hello. What metals is Contra wire made up of please?

Eureka wire (also known as Constantan or Contra)
Constantan is a copper–nickel alloy also known as Eureka,
Good to know Dr J. So, when would you use constantan and when nichrome? Not that we've got reels of both dating back to the bronze age in our inherited stash, or anything... Be good to know what each is best for, as I'm not as up on physics stuff as I'd like.
Constantan is an example of a metal whose resistance varies little in regard to temperature. Commercially, it is used in the manufacture of strain gauge sensors. You could use it in comparative studies with Nichrome, whose resistance does vary.

You can also use Nichrome in place of platinum for flame tests and make inoculating loops from it.
Nichrome wire can be used as an alternative to platium wire for flame testing by colouring the non-luminous part of a flame to detect cations such as sodium, potassium, copper, calcium,
also Nichrome makes nice heating coils as it oxidisies to chrome oxide
Nichrome makes nice "hot wire cutters for polystyrene foam"
Constantan I use in Metre Bridges for resistance work
(starting to think about school again as it's Thursday )