spectroscopic analysis lab

Today we did a lab that used spectroscopes to tell us the affect in transmittance that two different elements had at certain wavelengths. The elements were cobalt and copper. While we were testing the transmittance we also tested for absorbency. The spectroscopes( not telescopes ) were machines which you put a vial of water in and set the wavelength at its proper setting and had the transmittance for water at 100. Then you change the water vial out for the cobalt or copper vial and check for transmittance and absorbency. Making sure the vial has no fingerprints or else the data will be bad.