[SCA-Dance] Source of quote about La Volta

[Joanna and Murray]

I've been asked about the source of the "murders and miscarriages" quote below. 

I haven't a clue. Can anyone help?

Joanna

 > Here's the quote about La Volta that I told you about. Do you think
> anyone on the dance list might know the original source for this? The book 
> I've got it from is frustratingly vague about its research.
>
> Obviously, it's not the whole quote from the book I'm looking for, only 
> the bit at the end. I only included the rest so you could have a sense of 
> the context. If the rest of the book is anything to go by, this "critic" 
> was someone in the 16 century, or the author would have specified 
> otherwise.
>
> "Dancing was the public court activity /par excellence/, and the queen's 
> [Elizabeth I's] enthusiasm for this social and moral form of exercise 
> lasted well into her old age. 'I assure you,' wrote one courtier from the 
> 'warm winter box' of Richmond Palace, 'six or seven gallyards of a 
> morning, besydes musycke and syngynge, is her ordinary exercise.' Queens 
> were rivals even in these activities. The famous portrait in Penshurst 
> Plalace of Elizabeth dancing /La Volta/, supported by Dudley, Earl of 
> Leicester, is in fact an English transposition of an earlier French 
> painting featuring Marguerite de Valois in identical posture. One critic 
> claimed: 'The Voltas which magicians have brought from Italy have this 
> misfortune, that a great many murders and miscarriages result from them. "
>
> Quoted from */_Music at Court_/*, Christopher Hogwood. London, The Folio 
> Society, 1977.