On October 23, 2012 I searched WorldCat for this edition of Voltaire's "Philosophical Dictionary" and only 2 libraries, U of Illinois and U of Virginia, had a copy of this edition and the U of Illinois copy was declared missing as of 08/03/98.
If you think dictionaries just give the definitions of words, then you have not read the dictionaries of Bayle, Brewer, Voltaire, Lempriere, Seyffert, Anthon, McCabe et al.
From publisher's ad: "This is the largest and most correct edition in the English language, having, besides the whole of the London Edition, several articles from a manuscript translated several years since by a friend of Voltaire's, and others translated immediately from the French Edition."
The copyright for this work was held by John Quincy Adams and was registered in 1836.
The 2007 edition of Voltaire's Philosophical Dictionary is a digital edition (PDF file) of the 1874 edition, edited by Abner Kneeland and published by J. P. Mendum.
John Morley, in his book simply entitled Voltaire, wrote “When the right sense of historical proportion is more fully developed in men’s minds, the name of Voltaire will stand out like the names of the great decisive movements in the European advance, like the Revival of Learning, or the Reformation.”
Robert Ingersoll, wrote about Voltaire that “he was the greatest man of his century, and did more to free the human race than any other of the sons of men.”
Victor Hugo wrote, in his Oration to Voltaire, that “he was more than a man, he was an age.”
Will Durant, perhaps taking his cue from Hugo, titled the 9th volume of his 11 volume Story of Civilization “The Age of Voltaire."
John R. Iverson writes in his Barnes and Noble 2006 version of Voltaire's Philosophical Dictionary, which is only 438 pages, that "the basic translation was taken from the 1901 E. R. Dumont edition of 'The Works of Voltaire.'" We have this 1901 edition and it is 10 volumes of roughly 300 pages per volume. Look for this 1901 edition on these pages in the near future.