Seed Heads

In addition to the mineral samples collected from the 1993 formation, a number of wheat seed-heads were also collected that had received a ferrous coating.  The sample supplied by Peter Sørensen had a coating that had penetrated and filled the gaps between the base of each seed and the central stalk.  It was also noted that there was infiltration under the outer glumes of the seed  heads. 
At the time, this degree of penetration seemed surprising and certainly would not have occurred if iron filings had been used. However, I suspected that the material in Irving's possession was fine enough to produced this invasive coating.
I wanted to verify this and reproduce the coating but, unfortunately, I only received the powder in September, 2004, and was unable to get some fresh seed heads. Instead, I had to use the seed heads shown on the left which were of unknown age. Initially, I had tried the tests on four other seed heads but they soon degraded and blackened as a result of bacterial attack.   This occurred because I was using old organic material, so, to prevent its recurrence in the above seed-heads, I pre-treated them in 10% formaldehyde solution - a bactericide that should not influence the test results.  Whilst still damp and held horizontally, all seed-heads were then dusted with iron powder from a height of about 70 cm.   All seed-heads were coated to approximately the same degree.   They were then kept in a damp atmosphere for five days and examined.

The first observation was the striking discrepancy in the degree of rusting.   It is not clear why this happens but it has been a recurrent feature of all the tests.

This test was stopped prematurely because the seed-head on the left had become badly discoloured.  At that stage, the sample on the right showed little signs of rusting.
In all cases, the initial dusting of iron powder had penetrated to the central stem. However, powder also tended to accumulate there by what appeared to be gradual migration caused by droplets of water accumulating on the glumes and then flowing towards the stem, carrying the powder with them.   The sample on the right is the second from the left in the above picture. 

Initially, this sample was evenly covered but, with time, the coating on the upper seeds migrated towards the central stem.   As can be seen, the gaps between the seeds in these samples are far greater than those collected from the 1993 formation.   They were probably different varieties.   Also, the glumes on these samples became degraded during these tests whereas, in the originals samples, the glaze was applied to crop that was relatively fresh.  I propose to repeat these tests next season on fresh samples but I suspect that they will only confirm my present view that the iron dust in Rob Irving's possession could easily have penetrated to the central stems of the seed-heads in the 1993 Yatesbury formation.

On the next page, I examine one of the myths of this episode; namely, the story that, in places where it was thick enough,  the H-glaze had flowed across the ground.