she was among those who discussed a hypothetical planet perturbing uranus. in the 6th edition of "connexion" (1842) she wrote, "if after the lapse of years the tables formed from a combination of numerous observations should be still inadequate to represent the motions of uranus, the discrepancies may reveal the existence, nay, even the mass and orbit of a body placed for ever beyond the sphere of vision". predictions were fulfilled in 1846 by the discovery of neptune revolving at the distance of 3,000,000,000 miles from the sun. "the mass of neptune, the size and position of his orbit in space, and his periodic time, were determined from his disturbing action on uranus before the planet itself had been seen." "connexion" ran to 10 editions, more than 9,000 copies and was its publisher's most successful science book until "the origin of species" by charles darwin in 1859. it was translated into german and italian and went through various editions in the united states.