Proceedings qf the Royal Society. 19T 



The author proposes, by a formula, to represent the length of 

 path described by an average muscular effort at a given angular 

 nscent in a given time, and which, multiplied by the sine of that 

 angle, will give the vertical height gained. 



Direct experiments are quoted, to shew the uniformity of verti- 

 cal ascent within the usual limits, viz. between 12" and 23°. From 

 the known results of tread-mill experiments, it is supposed that the 

 diminution of effective action at a vertical ascent is not very consi- 

 derable, but may yet amount to about 1100 feet per hour ; whilst 

 about 20°, the effective action will be nearly 1500 feet per hour. 

 The horizontal action is estimated at about four miles per hour. 

 Tiie following formula sufficiently represents extensive experiments 

 at various angles of ascent, h = height ascended in English feet in 

 an hour, at an angle « : — 



h = { -. — 7 — r-75^ — 800 sin. tn > sin. x. 

 ^ sin. (a + 6 ) ^ J 



2. Observations on some New Species of British Fishe?. By 

 Dr Parnell. 



March 6. — Sir Thomas M. Brisbane, Bart., President, in 

 the Chair. The following communications were read: — 



1. On the power of the Periosteum to form new bone. By 

 Professor Syme. 



The object of the author in this paper is to state certain obser- 

 vations and experiments by which he considers it to be clearly es- 

 tablished, that the periosteal membrane, covering the bones, has the 

 power of secreting osseous substance, and of forming new bony 

 matter. 



Duhamel, founding on a false analogy, which he supposed to 

 exist between the periosteum and the bone on the one hand, and 

 the bark and wood of trees on the other, was the first to lay down 

 distinctly the theory that bony matter is formed by the investing 

 membrane of the bones. The experiments and observations of 

 Haller and others on the progress of ossification in young animals 

 were believed, however, to militate against this idea, and tended 

 rather to establish the doctrine, that new bony matter is formed by 

 the pre-existing or old bone. Between these two theories, the 

 opinions of physiologists and surgeons are still pretty equally di- 

 vided. 



The author was lately induced to suspect, from tlio circumstances 

 of a case of necrosis, that the theory of Duhamel is the true one. 



