Specific heat is an intensive property (like density, color, etc.) that does not depend on the amount of a substance present. This allows substances to be identified using their specific heat.
Imagine an unknown metal of known mass is heated to a known temperature. The heated metal can then be placed into a sample of water for which the volume (and therefore mass since 1mL=1g) and temperature are known.
The amount of energy (Q) transferred to the water can be calculated by using the equation #Q_w=m_wC∆T_w# since the mass (m) and ∆T(temp change) can be measured.
This allows for a calculation of the C value for the metal since the head gained (Qw) of the water will equal the heat lost by the metal (Qm).
The C value for the metal allows the metal to be identified.