VOL. XLIII.] PHILOSOPHICAL TRANSACTIONS. !^ 



posed to have been already drawn outwards to the length /, and, in restoring it- 

 self, to draw the body after it : only, in this latter case, v, the initial velocity in 

 the proposition, will now be the final velocity, as above. 



Our proposition equally holds good, when the spring is of any form whatever, 

 provided l be always understood to be the greatest length it can be bent or drawn 

 to, from its natural situation, / any less length, and p, p, the forces which will 

 confine it to these lengths. For Dr. Hook's principle extends to springs of any 

 form. 



Dr. J. has drawn so great a number of corollaries from this proposition, because, 

 in the controversy about the force of bodies in motion, both parties support their 

 opinion by arguments taken from the theory of springs. 



Of a Steatomatous Tumour of the Ovarium, in which Hair iv as found; by Albert 

 Haller, Professor of Anatomy and Botany at Gottingen, &c. From the 

 Latin. N° 472, p. 71- 



The subject of this communication was a maid servant, who died after a very 

 lingering illness. On opening the body, the first thing which struck professor 

 H. was a large tumour in the pelvis, which he suspected to be occasioned by 

 pregnancy ; but on examination, it was discovered to be a morbid enlargement 

 of the right ovarium. Hydatids were found adhering to this tumour ; and on 

 cutting into it, it was found to consist of a hollow sac or cyst, divided by a sep- 

 tum into 2 cells. The smaller cell contained a matter resembling honey, and a 

 substance resembling fat, together with a great quantity of brown, curled hair, 

 like human hair : these hairs were nearly 2 inches long. Some of this honey-like 

 matter, the meliceris of the ancients, being put into the fire, it burnt like fat. 

 The larger cell contained a milky, purulent fluid, in which were suspended some 

 brown, friable lumps, resembling portions of lung. 



Professor H. supposed this double tumour to have been formed by the morbid 

 enlargement of 2 ova or vesiculae, which went on increasing until they occupied 

 the whole cavity of the ovarium. He thought it not so easy to account for the 

 presence of fat and hair. From this case he was inclined to doubt whether the cu- 

 ticle be essential (as is commonly supposed) to the formation of the cortical part 

 of the hair. He did not think the hair had belonged to a foetus dissolved by pu- 

 trefaction, as no teeth or other solid body was found with it.* 



• Other instances of hair contained in the ovarium have been recorded by Dr. Tyson (Phil. Col- 

 lections, N" 2, or vol. ii. p. 490 of these Abridgments), by Mr. Yonge (Phil. Trans, vol. xxv. N" 

 309, or vol. v. p. 347 of these Abridgments), and by Dr. Baillie. (Phil. Trans, vol. Ixxix.) Sec 

 also Trans, of the Royal Irish Academy, vol. i. 



