Megilp

[Robert Garrett]

I see references to this, and from my understanding it is made with a drying oil, some say linseed oil boiled with lead, and mastic varnish, I'm not interested in using this to paint just to expand my knowledge of what it was that JMW Turner actually used. Though I do know this was used quite extensively in the late 1700-s to mid 1800's.

Any information would be greatly appreciated.

RG

[George O'Hanlon]

Megilp and its many variations, such as gumtion and Robersons' Medium, were commonly used by painters in the late 18th century and throughout the 19th century. It is a mixture of linseed oil in which litharge (lead oxide) is boiled and then mixed with mastic varnish.

[Saturn]

Robgar,
The medilp that J.M.W. Turner used was in most of the cases actually Gumption. Gumption is one of the variations of Megilp ( nowadays called Maroger Medium). It is pure unboiled linseed oil mixed with concentrarated watery solution of lead acetate. Then to this mix is added concentrated sulution of mastic resin in oil of turpentine.
The resulting jelly is very light in colour and is said to be more permanent than the standart dark form of Megilp.
Other variations of Gumption were prepared not my mixing watery solution of lead acetate and linseed oil, but by grinding the acetate powder and the oil together with the subsiquent addition of mastic varnish.

[Orp]

I've made many batches of Maroger's. Never with Lead Acetate. This sounds like a very old school formula from the days when you could buy Lead White from Dutch Boy.

There are more directions around in how to mess it up than make it correctly. Anyone who thinks there is a reaction that occurs at 550F just doesn't know what they're doing. I've always heard of precipitation falling out when making Maroger's but I've never run into this problem using chemically pure PbO. In fact it is always blonde and luminous. I think the only reason why I stopped using it was just because I had to do a new batch every month to keep it fresh.

[Kenneth Freed]

Saturn
Maroger medium as written by Maroger in his book indicates that the oil was to be cooked with lead. It says nothing about a watery solution of lead acetate.

[Saturn]

Mr. Freed,
I did not say that Maroger medium and Gumption are the same thing. Instead I said that Gumption is variation of Megilp. That is they all including Megilp, Gumption and the Megilp with another name ( Maroger) are of the same family- the family of gelly mediums including linseed oil, mastic and lead in one or another form. I am very well familiar with the so called Maroger medium because I have used to make it and use it many years in my own studio.
Turner used more often Gumption, not Megilp( Maroger)
It is the Gumption that is prepared using lead acetate with or without water and linseed oil .Not Maroger(Megilp)

[Saturn]

[QUOTE]Originally posted by Orp:
[QB] I've made many batches of Maroger's. Never with Lead Acetate. This sounds like a very old school formula from the days when you could buy Lead White from Dutch Boy.

Orp, actually this recipe for Gumption is much older than this. I do not encourage you to get involved with lead acetate. It is much more toxic than other forms of lead because of it`s soluble nature and can be absorbed through healthy skin in a much greater measures as compared to other forms of lead.
Also it is years already that I do not use Megilps in any forms. I found that I can achieve the same or even much better effects without it.

[Robert Garrett]

Thanks for the info, As I've said i've no interest in making this stuff, just looking for better understanding of Turners materials. I greatly appreciate all of the input.

RG

[Robert Garrett]

I found this reference to the megilp of turner, and this at least leads us to the conclusion that it is lead acetate and not one of the other forms of megilp


In the cse of J.M.W Turner's "the opening of the Wallhalia 1842" a low melting-point component was detected. This was later identified by Direct Temperature Resolved Mass Spectometry (DTMS) as spemaceti wax. On the basis of knowledge of artists palettes and materials available at the time it is likely to be the original material uses. Turners use of oil and ressin mixtures referred to as "megilp", are, however, not distinguishable by thermomicroscopy alone from oil paint with lead driers or oil with some resin added, though the groups are distinguishable from unmodified oil medium. Resi-rich lead acetate megilps have been found by DTMS in yellow glazes in "The Opening of the Wallhalla 1842"

Handbook of thermal analysis and calorimetry: applications to inorganic and miscellaneous materials
By Patrick Kent Gallagher, Michael E. Brown, Richard B. Kemp

Page 55 3.1.1