294 



and the author states his reasons for believing that the branchial fila- 

 ments are the principal absorbing organs, the materials they receive 

 being chiefly employed in the construction of the electrical organs, 

 while those which enter into the composition of the body generally 

 are absorbed by the general surface of the foetus. The author is led, 

 from his researches, to the conclusion that the mode of reproduction 

 in the Torpedo is intermediate between the viviparous and the ovo- 

 viviparous. 



In the second part of the paper, the author discusses the question 

 as to the number of species of the genus Torpedo existing in the Me- 

 diterranean ; and concludes that there are only two, viz. the Ochia- 

 tella and the Tremola. 



4. "Appendix to a former Paper on Human Osteology." By Walter 

 Adam, M.D. Communicated by Dr. Prout, F.R.S. 



This appendix contains linear representations of various dimen- 

 sions of the bones of the human body, both male and female, with a 

 view to facilitate the comparison of the human frame with that of 

 other animals, and reduce it to definite laws. The author states that 

 many of the rectilinear dimensions of human bones appear to be mul- 

 tiples of one unit, namely, the breadth of the cranium directlv over 

 the external passage of the ear ; a dimension which he has found to 

 be the most invariable in the body. No division of that dimension 

 was found by him to measure the other dimensions so accurately as 

 that by seven, or its multiples. Of such seventh parts there appear to 

 be twelve in the longitudinal extent of the back, and ninety-six in the 

 height of the whole body. 



5. " On the Repulsive Power of Heat." By the Rev. Baden Powell, 

 M.A., F.R.S. , Savilian Professor of Geometry in the University of 

 Oxford. 



The expansion of bodies by heat appearing to imply a mutual re- 

 pulsion of their particles, it becomes a question whether such repul- 

 sive power may not be excited by it between particles or masses of 

 matter, at sensible as well as insensible distances. After noticing the 

 partial investigations of this question by Libri, Fresnel, Saigey, and 

 Professor Forbes, the author describes the methods he has employed 

 with a view to its solution, and which consisted in applying heat to 

 two lenses of glass, pressed together so as to exhibit the colours of 

 thin plates; the variation of the tints furnishing exact indications of 

 the most minute changes of distance between the surfaces, by what- 

 ever causes they may be produced. The conclusion he deduces from 

 his experiments, conducted on this plan, is that the separation of the 

 surfaces is of a different character, and is greater than can be accounted 

 for by the mere change of figure produced by the heat; and is therefore 

 in part to be ascribed to a real repulsive action between the surfaces of 

 the glasses derived from the power of heat. He also found, on trying 

 similar experiments with glass in contact with a metallic surface, that 

 the results were considerably influenced by the radiating power of the 

 latter ; the effect being increased when this power was greater, and 



