Based on my memory and elderly textbooks, I can offer a chemist's view in reply to some of Eric Parson's questions.
Copperas = Green vitriol = ferrous sulphate heptahydrate = FeS04,7H2
(Note: Copperas has nothing to do with the element copper.)
Copperas can be made by the slow oxidation, in presence of water, of iron disulphide, FeS2, aliases pyrites or marcasite. Iron disulphide was clearly present in the area, conditions were ideal for copperas to be formed in situ in the strata present. Some could even have formed in pellets akin to the starting iron disulphide, and some leaching could have occurred giving rise to green/blue staining if it evaporated.
Extraction of rock containing copperas with water would yield a dilute solution which could be concentrated by evaporation and then crystallised to give the pure green solid copperas. This is what Dale described as quoted by Eric.
In the early 18th Century the most convenient way to make sulphuric acid was by distilling copperas (oil of vitriol and green vitriol respectively); indeed this method reigned supreme until the early 19th Century when the lead chamber process made sulphuric acid a tonnage chemical. Hence the reason why the locals were keen to process copperas.
Mention of blue vitriol (copper sulphate) is clearly an error. In fact in the 18th Century copper sulphate was made by reacting dilute sulphuric acid (made from copperas) with basic copper carbonate, alias malachite.
The connection between Portland Cement and sulphuric acid arises because the coal used to fire cement clinker contains some sulphur. The sulphur burns forming sulphur oxides which have to be scrubbed from the exhaust gases thus giving rise to dilute sulphuric acid.
Douglas Harper
I read with interest the article on black rabbits (White Admiral 40).
Tom and Catherine may be interested to know that I too have seen black rabbits in their area. I have also seen them in the small village of Blyford in a field beside the B1123 road into Halesworth (TM 412773). I recorded them here in 1997 and again this year, and have been told by a nearby resident that they have been here for many years. The numbers of black rabbits seen have not increased. The field is located right next to dwellings.
Colin Jacobs
As a postscript to my article in Newsletter No. 39, I am delighted to write that in June 1998 I was at last able to enjoy seeing both the male and female of this nationally scarce dragonfly in its stronghold in the north of the County.
The name of this dragonfly is most certainly appropriate as far as Great Britain and Ireland is concerned since it can only be found breeding on a few scattered river systems and adjacent still-water sites in the south and east of England. Until 1997, records of L. fulva in Suffolk had only been confirmed from the grazing marshes along the R. Waveney. However, it has come to my attention (per Steve Cham, British Dragonfly Society and Regional Recorder, Anglia region), that this year two males were sighted in the Stour valley by a British Dragonfly Society member from Cambridgeshire. Acting on this information, Steve found two more males near Bures in July 1998. It therefore seems that we have a breeding population somewhere along this river. For such a vulnerable species this is excellent news indeed. Hopefully, Suffolk dragonfly enthusiasts will wish to follow up these sightings and it would be marvellous to read of further finds in the summer 1999 issue of White Admiral.
(Records should be sent to the SBRC - see page 40)
Steve Goddard
During the morning of Sunday 25 October, 1998, whilst walking with Jack Wylson along the north-eastern edge of Waveney Forest, Fritton (TG 458010) past Birch scrub, we came across some 20 Common Darters (Sympetrum striolatum) actively flying around a footpath. Along this stretch of path there were a series of puddles less than ½ an inch deep and approximately four foot in diameter. As we neared one of the puddles we saw a pair of Common Darters in tandem at its edge. Still in tandem the female was actively laying eggs at the edge of the puddle and was seen to carry on with this procedure for up to a minute until disturbed by dog walkers. Once the dog walkers had passed, the pair moved on to another puddle and the female continued to lay eggs. These puddles are only formed after rain so the eggs will not survive. The only other water source in the vicinity was the River Waveney, 150 yards from the puddles.
The only record of unusual oviposition by this species that I am aware of is a published account by H.E. Jenner of Herringfleet in Suffolk Dragonflies (Mendel, 1992) who stated that a female attempted to lay eggs on polythene.
Colin Jacobs