Who discovered that dna was the genetic material or transforming factor that could convert nonvirulent r-type streptococcus pneumoniae bacterium to the virulent s-type?

Discovery
               In 1928 it was discovered by Frederick Griffith in an experiment generally known as transformation.

Experiment
                   In his experiment he considered two strains of streptococus pneumonia, one was R-type which was non-virulent and cause no disease in mice, other was virulent and S-type which cause disease and at last death of mice.
This experiment was comprised of four steps which are as follow:

 Step 1:
           First he injected living strain of S into mice, after sometime mouce died.

Step 2:
          He injected living strain of R into mice, the mice alive as he did not got any disease.

Step 3:
         He injected heat killed strain of S into mice and mice remain alive.

Step 4:
           He mixed living R strain with heat killed S strain and then inject into mice. As a result the mice died.

Conclusion:
                  It was found that genetic material from heat killed S stain were transferred to living R (non-virulent) strain, as a result R become virulent and cause the death of mice.

What is the question? if you were looking to design a method of separating something, you can separate this compound by putting both in water and allowing the water to dissolve the sugar. then pour it into another beaker and evaporate it then boom! salt and sugar : )