268 



and new properties of the cone and the sphere are made most clearly- 

 manifest, and numerous practical results are very readily obtained by 

 the application of a double scale of sines to the rays of the cone — 

 distributed equally on the plan — correspondingly on the elevation, and 

 on the developed surface, or on any other projection of the cone. 



He considers that it is of great importance that some method 

 should be devised to give appropriate names to these new curves, 

 especially those so evidently and intimately related to old ones. 

 Thus the curved intersection of a cone and a sphere, from which the 

 cardioid is projected on the base, and which has then the cusp turned 

 symmetrically inwards, by another projection on a vertical plane 

 gives a symmetrical line with the cusp turned outwards, having 

 other distinct points of change in the curvature. 



As ellipses are related to cardioids, so it is stated are hyperbolas 

 in a similar way related to conchoids ; conchoids to their mechani- 

 cal reciprocals ; and parabolas to cissoids ; amongst the vast number 

 of curves, any of which can conveniently be derived by scales prac- 

 tically from the cone. 



By this method it is considered that not only projections of curved 

 sections of cones, spheres, &c. are obtained with ease, but also by 

 means of scales, ruled papers, hollow cones and diagrams, the plane 

 sections of cones, and all projections from them are greatly facilitated. 



In conclusion the author remarks, that if this subject can be en- 

 tertained by the Royal Society, he will make copies of a series of 

 diagrams to illustrate what he has here stated in reference to scales 

 applied to cones to obtain cardioids, &c. 



December 16, 1852. 

 J. P. GASSIOT, Esq., V.P., in the Chair. 



A paper was read, entitled " On the Solution of Urinary Calculi 

 in dilute Saline Fluids, at the temperature of the body, by the aid of 

 Electricity." By H. Bence Jones, M.D., F.R.S., Physician to St. 

 George's Hospital. Received Oct. 12, 1852. 



In 1848 the author first attempted to dissolve calculi in a solution 

 of nitrate of potash, by placing them at the same time between the 

 electrodes of a galvanic battery ; an effect was produced on the uric 

 acid at the negative pole, but no very decided result was obtained. 

 The experiments were resumed during the last summer. 



The results with uric acid calculi may be thus arranged. The 

 action was chiefly at the negative electrode. 



Experi- Duration of 







Power of 





ments. experiment. 



Strength and temperature of solution. 



Battery. 



Result. 



h m 





o 





grs. 



1. 4 



Saturated solution of nitre 



212 



... 10 ... 



0^ dissolved. 



2. 6 5 





109 



... 5 ... 



11 



3. 6 10 





101 



... 10 ... 



14 



4. 6 20 





100 



... 10 ... 



16 



5. 6 45 





106 



... 10 ... 



12 



6. 3 17 





98 



... 20 pah- 



27i 



