406 Royal Society. 



By ascertaining the distances at different azimuths at which a bar 

 magnet placed with its axis directed to the centre of a magnetic 

 compass needle caused the needle to assume the position in which 

 its axis was in the same line with that of the magnet, the author 

 found that these points of distance form a peculiar curve, which was 

 nearest to the centre of the magnet at the east and west azimuths, 

 and receded from it as it advanced to the north and south ; and was 

 twice the distance from it at the north than at the south azimuths. 

 From this and other experiments he infers that the value of every 

 degree of the compass is inversely as the square of the length of the 

 ordinate or co-ordinate passing through it, the abscissa being con- 

 sidered as zero ; and that the magnetic needle does not rest in the 

 magnetic meridian in consequence of polar attraction, but is im- 

 pelled in that direction by the effect of repulsion, from the east or 

 west, and that its natural position is the result of an equilibrium 

 between the eastern and western repulsions. On the other hand, 

 the return of the needle, when it is placed in the reverse position, 

 that is, when made to deviate 180° from its natural position, is the 

 result of an attraction towards the east and west positions ; the force 

 of attraction in that case being quadruple the force of repulsion in 

 the former case. He is consequently led to the conclusion that the 

 operation of terrestrial magnetism is totally different from that of an 

 artificial magnet, in which latter case the attractive and repulsive 

 forces are exactly equal. 



" Remarks on the Extractive Material of Urine, and on the Ex- 

 cretion of Sulphur and Phosphorus by the Kidneys in an unoxidized 

 state." By Edmund Ronalds, Ph.D., Giessen. Communicated by 

 Golding Bird, M.D., F.R.S. 



In the course of an experimental inquiry in which the author 

 was engaged with a view to ascertain whether larger quantities of 

 carbon were discharged by the kidneys in cases in which the func- 

 tions of the lungs or liver were imperfectly performed, he was led 

 to the result, that sulphur, not combined with oxygen in the form of 

 sulphuric acid, existed in the urine to the amount of from three to 

 five grains in the course of a day ; and also that phosphorus, not in 

 the state of phosphate, was in the same period excreted by the same 

 channel, to the extent of nearly six grains. 



" On some peculiarities of Foetal Digestion." By George Robin- 

 son, M.D. Communicated by William Bowman, Esq., F.R.S. 



The author endeavours to show, contrary to the assertions of Dr. 

 Robert Lee, that the human foetus, in common with that of all the 

 higher animals, invariably contains, during the latter periods of 

 intra-uterine life, albuminous or nutritious matter, which undergoes 

 digestion in the small intestines. He finds that the nature of this 

 substance varies very much in different animals. In the earlier 

 periods of foetal life, the stomach contains very little, if any, nutri- 

 tious matter. He is disposed to consider the salivary glands as the 

 source of the albuminous matter found in the stomach at later 

 periods. 



" Extracts of Letters from Captain Williams, first Assistant to the 



