Points in a Programme of Physics. 



455 



strength is reached, the subcryohydrate is produced continu- 

 ously with the further separation of ice. The one set of 

 crystals floats, the other sinks. This occasional state of things 

 is the most perfect counterpart of the simultaneous separation 

 of water as vapour and the salt when a saturated solution 

 boils, considered in § 140. A drop or two of the same solu- 

 tion, suddenly cooled to opaque solidification, determines the 

 formation of the true cryohydrate. 



I beg the reader to note the following corrections of, and 

 additions to, Table X. § 88. In the case of correction, the 

 corrected number is marked with *, the previously given 

 number being placed in brackets. 



Formula of salt. 



Temperature 

 of cryogen. 



Temperature 

 of solidification 

 of cryohydrate. 



Water- 

 worth. 



Per cent, 

 of salt. 



Add CaCl 2 +3H./) 



Correct... Nal " 

 Correct... NH 4 C1 



Add AgN0 3 



Correct... K^Og 



-33 



-26-5 



-16 



- 6-5 



- 3 



-37 



-30* (-15) 

 -16* (-15) 



- 6-5 



- 3* (-2-6) 



11-8 

 8-6 

 12-4 

 10-09 

 44-6 



36-45 



49-2 



19-27 



48-38 



1120 



LIII. Points in a Programme of Physics. By Don Enrique 

 Serrano y Fatigati, Professor in the Instituto National, 

 Ciudacl Real. Abstracted and communicated by Edmund J, 

 Mills, D.Sc, F.R.S* 



Introduction. 



THE recent history of science is one of accumulations, 

 bedimmed by detail. As we survey it, we observe a 

 twofold confusion — that arising from the admixture of innu- 

 merable single items, and that which is due to the interference 

 of imagination. Thus even its facts have become tinctured 

 with a kind of unreality. And, while unquestionably admit- 

 ting that without observations and quantitative measurements 

 we cannot acquire an adequate knowledge of phenomena, it 

 must equally be allowed that without philosophical investigation 

 we must constantly wander in an inextricable labyrinth of 

 facts. But a part of the confusion is traceable to our taking 

 into account the Being, Form, Essence, Causality, &c. of 

 things : and these cannot possibly be reduced to experiment. 



* From the Revista de la Univei'sidad de Madrid, (2) v. 61. A further 

 development of the author's views, of more especial interest to the mathe- 

 matical reader, is given in Una Leccion de Fisica general (Madrid: Aribau, 

 1876, pp. 45). — I wish to record my indebtedness to Mr. C. Tomlinson, 

 F.H.S., who very kindly wrote me a translation of the whole of the diffi- 

 cult memoir here represented in abstract. — E. J. M. 



