Reply To: A Hello to Virology
That paper contains a great summary of Beijerinck’s findings:
“1. Crude extracts from diseased plants passing through porcelain filter candles do not show bacterial growth during three months of storage, but remain infective. Subsequent plant inoculation by injection readily leads to infection and reproduction of the characteristic
symptoms.
2. Unlike bacteria, the infectious agent diffuses laterally into agar for at least 2 mm.
3. The agent multiplies in plants, as shown by serial transfers from plant to plant, and cannot be a toxin.
4. The agent multiplies only in actively growing tissues. It is not able to grow by itself but is carried away by the growth of dividing cells where multiplication in the living protoplasm is enormous.
5. Transport is `through the phloem’, upwards and downwards according to laws directing the movement of nutrients; in stems it is primarily vertical with little lateral spread.
6. The agent resembles living cells in that it is killed at 90oC.
7. The agent may be dried in infected leaves (in an herbarium) and in filter paper soaked in infectious sap.
8. The agent may remain in dry soil during winter and infect plants from the soil; it can also be transferred in potting soil.”
9. The agent retains infectivity after alcohol precipitation from sap and subsequent desiccation at 40 oC.
Beijerinck didn’t believe his virus to be “corpuscular”, but instead referred to it as “contagium vivum fluidum”, or some kind of living fluid contagion.
A translation of that original paper can be found here:
https://www.apsnet.org/edcenter/apsnetfeatures/Documents/1998/