Some Additions to a Paper, Read in 1790, on the Subject of a Child with a Double Head. By Everard Home, Esq. F. R. S.

IV. Some Additions to a Paper, read in 1790, on the Subject of a Child with a double Head. By Everard Home, Esq. F.R.S. Read December 13, 1798. In the year 1790, I laid before this learned Society, an account of a child with a double head, illustrated by drawings, which is honoured with a place in the Philosophical Transactions, Vol. LXXX. Since that time, Mr. Dent, the gentleman who sent over from India the double skull, which was shewn at the meeting when the Paper was read, has returned to England. Among his drawings there are two portraits of the double head, taken by Mr. Devis, an artist of considerable merit, who was upon a visit at Mr. Dent's house, in Bengal, when the child was brought there alive, to be shewn as a curiosity. These drawings give a more faithful representation of the appearance of the double head, than the engravings annexed to the former Paper, and at the same time exhibit a striking likeness of the child's features. Mr. Dent has given permission to have them copied; and, from a desire to render as complete as possible, the account and representation of so curious and rare an instance of deviation from the natural structure in the human body, they are now offered to the Society, (see Tab. II. and III.) with some observations made by Mr. Dent, as a supplement to the former Paper. Mr. Dent's observations, in addition to those already in the possession of the Society, are the following. The child was a male. Its father was a farmer at Mundul Gaut, in the province of Bardwan, who told Mr. Dent, that it was more than four years old at the time of its death.* The mother, who was thirty years of age, had three children, all naturally formed; and her fourth child was the subject of the present Paper. Mr. Dent endeavoured to discover whether any imaginary cause had been assigned by the parents, for the unnatural formation of the child; but the mother declared, that no circumstance whatever, of an uncommon nature, had occurred: she had no fright, met with no accident, and went through the period of her pregnancy exactly in the same way as she had done with her other children. The body of the child was uncommonly thin, appearing emaciated from want of due nourishment. The neck of the superior head was about four inches long; and the upper part of it terminated in a hard, round, gristly tumour, nearly four inches in diameter. The front teeth had cut the gums, in the upper and under jaws of both heads. When the child cried, the features of the superior head were not always affected; and, when it smiled, the features of the superior head did not sympathize in that action. In preparing the skull, which unpleasant operation Mr. Dent was obliged, from the prejudices of his servants, to superintend, he found that the dura mater belonging to each brain, was continued across, at the part where the two skulls joined, so that * In the former Account, the child is said to have been about two years old at that time. each brain was invested, in the usual way, by its own proper coverings; but the dura mater which covered the cerebrum of the upper brain, adhered firmly to the dura mater of the lower brain: the two brains were therefore separate and distinct, having a complete partition between them, formed by an union of the duræ matres. When the contents of the double skull were taken out, and this union of the duræ matres more particularly examined, a number of large arteries and veins were seen passing through it, making a free communication between the blood vessels of the two brains. This is a fact of considerable importance, as it explains the mode in which the upper brain received its nourishment. Before these observations were communicated by Mr. Dent, it was natural to suppose that the two brains had been united into one mass; as it was difficult to imagine in what way the upper brain could be supplied with blood.