Abstract Thursday: "Organic"

Ingeborg's chosen topic for today's Abstract Thursday challenge is "Organic".

This photo started off as a shot of an old ice-cream tub about half full of broken eggshells. "Why are we collecting eggshells?" you may well ask. Well, it's a desperate attempt to make this year's crop from our veggie boxes more successful: over the last few years we've had an increasing problem of slugs and snails demolishing the crop almost like locusts!

Slug pellets are effective but we hate using them, partly due to the risk to birds who may eat the dead snails. We've tried steel wool wrapped round the bases of the plants - to no avail. Last year we tried pellets of compressed wool, specially made for the purpose: useless! Snails were supposed to hate gliding over them but within a day or two we found multiple snailtracks over them and the plants had been nibbled.

So now we've heard that crushed eggshells round the plant bases are supposed to deter them and we're therefore collecting the shells whenever we eat eggs. Fingers crossed.

"Are eggshells really organic?" I wondered. Well of course they do have an organic origin, but they're about 95% carcium carbonate which is an "inorganic" salt. However I looked them up and found that the other 5% of the shell is made up of hundreds of different proteins that affect how the calcium carbonate crystallises. Research published 2 years ago provided more fascinating details. One of the critical proteins is osteopontin which causes misalignment of the carbonate crystals, making the shells stronger as any crack would have to zigzag between the crystals rather than just splitting in a line. Although shells are only 1/3 mm thick they have inner layers with less osteopontin content (and are therefore smoother for the developing chick) and an outer layer with more osteopontin making it more durable.

As the chick matures the shell's inner layers begin to dissolve, supplying calcium to help the chick's bones to develop, and thinning the shell making it ultimately easier to crack.

Isn't nature wonderful?

(I got this info from this webpage and this research article if you want to read more about it.)


The photo was abused using the oil paint, emboss and solarise filters in Photoshop.