This work saved the French silk industry, which had been crippled by the disease pébrine. After three years of research on the problem, Pasteur was able to show that the disease known as pébrine was caused by a parasite, and that the disease known as flacherie, which authorities had thought to be a manifestation of pébrine, was in reality a bacterial disease with its own character and etiology. He developed a screening method, still used today, that employs systematic microscopic examination to separate infected silkworm eggs from healthy ones.