It was evident that these new and super-active bacteria attacked the soil, disintegrated all the nitrogenous compounds within their range and thus left the plants without nourishment. The death of the plant followed as a natural result; but the matter did not end there. By destroying the nitrogenous compounds in the soil, the bacteria altered the whole texture of the earth in which they grew. All the nitrogenous organic matter which forms so large a part of the binding material of some soils was destroyed utterly; with the consequence that the mineral particles, which previously had been resting in an organic matrix, were now free to move. Only the clays retained their tenacious character: all other soils degenerated into sand. There has, of course, been a great deal of speculation upon the origin of _B. diazotans_. Hartwell suggested that it came to us from Venus, propelled by light-pressure across the abysses of space. Inshelwood put forward the view that in _B. diazotans_ we had an example of bacteria, originally endemic, changing their habits and spreading into fresh regions. Personally, I believe neither hypothesis. I feel sure that I saw the birth of the first _B. diazotans_ on that night in Wotherspoon’s laboratory, under the action of the fire-ball; and the evidence is simple enough. Every living creature is a wonderfully constructed electrical machine. Each beat of our hearts, each systole of our lungs, each contraction of a muscle in our frame produces a tiny electrical current. Our organism is a mass of colloids and electrolytes which transmit these charges hither and thither throughout our systems; and were we gifted with an electrical sense in addition to those which we already have, we should see each other as complexities of conductors along which currents were playing with every movement of our body. This complex electrical system is acutely sensible to external electrical conditions. Anyone who has held the handles of an induction coil or who has taken a spark from a Leyden jar knows the physiological effects which these things produce. The influence of high-tension currents upon the growth of plants has been proved beyond dispute.