Royal Society. /^.^g 
and if it Hiould be all edged that infants far gone in the rickets 
are frequently oblerved to have great heads in proportion to their 
emaciated Imall bodies 5 and that young children are alio liable 
to another malady called Hydrocephalus or dropiy in the head, 
which Ibmetinncs fo dilates it, as to fwell the IcuU to a yet more 
immenle fize • but neither of theie diforders, orherwile affe(5l 
the head, than by a preternatural collection of ierous humours 
inclofed in the brain, which extend the yielding fides of the 
weak and tender Icull, but do not in the IcaU: increaie its bony 
lubftance j nay, on the contrary, rather diminifh it^ being as is 
always oblerved, reduced to a more than ufual thinnels, being 
Ibmetimes, no thicker than an egg-fliell, or piece of parchment^ 
nor can luch diftempers poflibly affedl: adults, fo as to enlarge 
their icuUs 5 becaule, all the bones are by that time become folid, 
and firmly knit together, lb as to be no way capable of further 
growth or extenlion j and hence it is, that thele maladies are in- 
cident to children, whilft their fculls are foff, pliable, and truly 
membranous, rather than bony j and daily experience aiTures us, 
that unlels fuch dileales be timely removed by the phyfician or 
furgeon's art, or overcome fo early by the ftrength of nature, as 
that the children have time enough to outgrow this difproportion 
in their heads, by the bulk of their body coming up to it, before 
it ariles to too exorbitant a degree of magnitude, they all die in 
their infancy, and thele fculls are eafily diftingailhed fron all 
others, by the large Fontanel or opening in the mole of the 
head, that remains membranous, and never becomes like the refl 
of the fcull, a bony fubftance; and that they cannot pofTjbly ar- 
rive at manhood is plain 5 for this monftrous and unequal fweiling 
of their heads, meeting with no reftrainr, but Itill incrsafing, 
when it comes to fuch a certain degree, that its extravagant 
dimenfions become inconfiftent with the natural functions of the 
body, the animal oeconomy muft fink under the preiTure ot luch 
a load, and the whole machine tend to its diffolution; as not 
being able to bear any longer with fo highly morbid a dif- 
pofition, in fo principal, and fo extremely necelTary a part to 
life as the brain, the fountain of all fpirit, lenfe and morion: 
The Dr. does not deny, but that by one accident or other, fome 
difproportion Ibmetimes happens, between the head and the reft 
of the body, in luch as are grown up to the compleat ftature of 
man 5 yet a dilproportion of this kind, however confpicuous to 
the eye, and unleemly, is never lb extraordinary as to be confide- 
rable in itlelfj for the circumference of a m.an's head of th^ com- 
mon fize, is ulually about 22 inches, and jf we chance to fee one^ 
M m m 2 o^* 
