The Virus Story
The term “virus” comes from Latin for “poison, sap of plants, slimy liquid”. A non-living thing, in other words, writes David Quammen in Spillover . Evidence to the contrary came not from medicine but from agronomy! The tobacco mosaic disease had hit tobacco production. It was transferrable via the sap. Filter the sap using filters through which bacteria can’t pass. No effect. The filtered sap could still spread the disease. This thing was tinier than bacteria. A Dutch researcher, Martinus Beijerinck diluted the sap, and then infected another plant even with that diluted dose. Weirdly: “Whatever it was, (it) regained its full strength even after dilution.” That meant it was “reproducing itself”. No poison can do that. No by-product of a bacteria can do that. This was something else. Trial and error yielded new information: “In a container of filtered sap alone, it wouldn’t grow.” Which meant it wasn’t feeding on the sap: “It needed something e...