Which were discovered first bacteria or viruses?
http://en.wikipedia.org/wiki/Viruses#Discovery “In the late 19th century Charles Chamberland developed a porcelain filter with pores small enough to filter bacteria, yet retain all viable viruses.[7] Dimitri Ivanovski used this filter to study tobacco mosaic virus. He published experiments showing that crushed leaf extracts of infected tobacco plants were still infectious after filtering through such filters. At about the same time, several others documented filterable disease-causing agents, with several independent experiments showing that viruses were different from bacteria, yet they could also cause disease in living organisms. These experiments showed that viruses are orders of magnitudes smaller than bacteria. The term virus was coined by the Dutch microbiologist Martinus Beijerinck who showed, using methods based on the work of Ivanovski, tobacco mosaic disease is caused by something smaller than a bacterium. He developed with the term “contagium vivum fluidum” which means “sol