Propositiones de lithiasi tōn nephrōn

and it is treated more with difficulty when the affected bodies are thin, Galen, same place, chapter 11.

XXIIX.
It is generated more easily in fatter people, because the material from which the stone is usually generated can be held more easily: in thin people, it is usually propelled into the bladder.

XXIX.
Children are more prone to bladder stones: but old men and those more adult, to kidney stones, because in children, since the heat is strong, the expulsive faculty is robust, and the substance of the kidneys is soft and loose, it is propelled more easily to the bladder: in old men, the expulsive faculty is weak, and the flesh of the kidneys is drier and more compact, by which it happens that they are held longer and hardened more, as Hippocrates, On Diseases, book 6, comm. 3, text 15, and Aetius in the cited places teach.

XXX.
In the same way, women suffer more rarely from kidney stones on account of menstrual purges and the looseness of the passages.

XXXI.
Arthritic patients easily become nephritic, because they abound in thick and earthy matter collected through continuous crudities indigestion/undigested humors. The long recumbency on the back and kidneys aids the growth of stones in these people.

XXXII.
Grains gravel passed show that the stone is still friable and sandy, and then there is some hope that it can be broken and cured: but if nothing of the sort is passed, it signifies that it is quite hard (as is usual in an inveterate disease), and so there is no great hope of health.

XXXIII.
Stones that are round or smooth are excreted more easily than rough and angular ones, and patients are less tortured by them.