188 Mr. J. K. Ingram on New Properties 



(r.) A diaphragm apparatus was charged throughout with 

 mlphocyanide of potassium (K, Sg Cy). Upon the first appli- 

 cation of the current the action was brisk, but soon dechned, 

 and when 5^ cubic inches of gas had been collected from the 

 platinode and 1| cubic inch from the zincode it ceased. 

 There was a copious orange- coloured deposit in the zincode 

 cell and upon the plate which interrupted the progress of the 

 electrolysis ; no particular odour was perceptible in either of 

 the cells. The liquid filtered from the zincode became turbid 

 by exposure to the air, and deposited more of the yellow com- 

 pound. The clear liquid was again subjected to the current, 

 which it transmitted readily, and with the same phsenomena 

 as before. There could be little doubt that sulphocyanogen 

 was the anion transferred in this experiment. This part of 

 our subject still presents a tempting field for investigation, 

 from which however we were for a time diverted by an im- 

 portant class of facts which next fell under our observation ; 

 we have however since returned to the study, and are at pre- 

 sent engaged in researches upon the cobaltocyanides, and 

 other double cyanides, the results of which we hope ere long 

 to lay before the Society. 



[To be continued.] 



XXVIII. New Properties of Surfaces of the Second Degree. 

 By John K. Ingram, B.A.^ Trinity College^ Dublin. 



To the Editors of the Philosophical Magazine and Journal. 

 Gentlemen, 

 ''I^HE following extracts from a paper lately read before the 

 -^ Philosophical Society of Dublin may perhaps interest 

 some of your readers. The theorems which I announce are, 

 I believe, perfectly new; and some of them will be found, I 

 think, to possess considerable geometrical elegance. 



Being given two ellipsoids, reciprocal to each other (their 

 common centre being the origin of transformation), let us de- 

 scribe the focal conies of one of them, the axes of which we may 

 call a, b, c. Then in their planes describe the conies reciprocal 

 to them. On these new conies let two cylinders be constructed 

 with their generatrices perpendicular to the planes in which 

 their bases lie. Those cylinders may be called the cyclic cy- 

 linders of the ellipsoid ( — , -y-, — j : they possess many re- 

 markable properties which are all derivable, by means of the 

 polar transformation, from those of the focal conies. 



-2 + T2 H 2 — M 



