m 



WATER. 







larity of the liquefaction of ioa to that of fatty bodies or of the metal*, 

 "which in melting pais through intermediate stages of softness or 

 vioosity ; " ail it U remarked, also, that Sir J. F. W. llerschel, when he 

 term* regelation " a sort of welding" [H.MI., col. 603], appears to concur 

 in thu view. Mr. Brayley asks, in conclusion of this |<ort of the sub- 

 ject, " Are all oases of the union of two apparently solid surfaces of 

 the same substance by cohesive attraction cases of melting and rege- 

 lation, an in&mtesimaUy thin film of liquid being momentarily pro- 

 duced and as instantly solidified 1 " ; and having in dismissing the 

 philosophy of the union of two surfsoes of glaw followed the reasoning 

 of Professor J. Thomson, on the cause of regulation, he states, not- 

 withstanding, that he wishes to be understood as not adopting, 

 exclusively, any existing theory on the subject Admitting the 

 operation of cohesive attraction and consequent pressure in the first 

 instance, the phenomenon, with respect to glass, it U shown, readily 

 admits of explanation by the original view of Mr. Faraday with respect 

 to ice. [Ice, col. 814.] 



The object of Mr. Brayley 's second 'Note' does not, strictly belong to 

 the subject at present before us, but to preserve the sequence of the 

 whole inquiry in its bearing on the physics of water, we may mention 

 that he finds reason to regard the molecular constitution of glass as 

 being analogous to that of " water cooled below the freezing point, but 

 still remaining liquid, until by a tremor, or the percussive contact of a 

 solid body, or the mere contact of a crystal of ice, its temperature 

 rises to 82% and it becomes ice," or to that of a saturated solution of 

 salt in hot water. " If so," he remarks, " glass will be a substance in 

 which this state of arrested liquidity, or potential solidity, is perma- 

 nent." Instructive parallels are also noticed between the crystallisation 

 of water and that of glass and some other bodies, which are presented 

 by the experiments of Gregory Watt, and Faraday. 



It is observed in the concluding ' Note,' that " No crystalline body 

 has been longer or more extensively subject to human observation 

 than crystallised water, or ice. Its natural history and properties, as 

 science has advanced, have been investigated with increasing generality 

 and precision ; and they have finally become objects of that systematic 

 and exact research which characterises the present era of physical 



inquiry A most remarkable deficiency, however, still remains, 



apparently, in our knowledge of this substance : water in the ritreoui 

 eunditio* Ice ijlaa has ncter been observed. While we know the 

 antithetical vitreous state of so many different crystallised substances, 

 minerals produced by heat, salts deposited from aqueous solution, 

 neutral bodies of organic origin, and have great reason to believe that 

 that antithetical condition to crystallisation is universal, we have no 

 knowledge of it in relation to water or ice. My own attention has 

 been awake to the subject, without success, for many years. It would 

 seem to be scarcely within the bounds of possibility that the glossy 

 state of water, if possessing what we term solidity, should not, ere now, 

 either have been observed in nature, or have occurred and been 

 recognised in experimental research.'' 



Mr. Brayley inquires, " Docs this apparent deficiency in our know- 

 ledge exist because to use language recently introduced into physical 

 science the homoloyue of the glassy state of water is not what we 

 ordinarily term solid because the state of water cooled below 32, but 

 still liquid, is in fact the state which corresponds to the vitreous con- 

 dition of other bodies, and to the physical nature of perfect ordinary 

 glass F Is the one simply a case of potential solidity, and the other of 

 the confluent or equivalent state of arrested liquidity ? " 



In reply to the anticipated objection that the homology sought to 

 be established between liquid water below 32 and glass, is a forced 

 one, and after admitting that, in relation to each other, these are 

 extreme cases, he proceeds to show that intermediate terms of the 

 series are not wanting, some of them being supplied by sulphur and 

 phosphorus, and others, in a remarkable manner, by selenium, various 

 conditions of all three appearing to be homologues, at once, of both 

 the extreme terms here alluded to. Mr. Brayley suggests, finally, 

 " Should this hypothesis be verified, water below 82, or rather, 

 perhaps, from the temperature of maximum density downward* 

 through that of freezing, may have to be regarded as the vitreous 

 condition of matter ; and the causes of the peculiar characters of that 

 condition, its effects on the transmission of the vibrations of sound and 

 light, the oonchoidal fracture, 4c., may have to be discovered by 

 researches on it* molecular nature." 



In exposition!), whether of the progress or the actual condition of 

 nny branch of science, the student is perpetually remind, d of the 

 leswm which teaches the indissoluble and universal connection of 

 every part of nature with every other part. Subsequently to the 

 rtion of all the views on the subject of regelation, and the mole- 

 cular relations of ice and water, of which an account has beun (_ 

 the preceding columns, this truth lias been exemplified in a striking 

 and instructive manner, which may eventually make it requisite to 

 modify all existing conclusions on that subject and its applications to 

 natural phenomena. 



In the ' Proceedings of the Royal Society' for June 13 of the present 

 year (1861), vol. xi., pp. 243-247, appear* the abstract of an elaborate 

 paper (itself to be published in tl jrliic.il Tim. 



' Liquid l>ili'iinioii applied to Analysis,' by Mr. Thoma* (I 

 Graham, V.P.R.S., Master of the Mint. In thin he shows the value of 

 the process of diffusion and of the principle of diffusibilily iu water, oa 



affording the means of bringing out clearly the distinctive properties of 

 what appear, in hi* judgment, to be two great divisions of chemical 

 substances. Mr. Graham's former researches on DIFFUSION have been 

 noticed in the article on that subject As this will be the only 

 tunity the near completion of our work will allow of giving an n< 

 of hid new results, we shall cite so much of his abstract as, in a- 1 

 to what is required for the subject of the present article, will suffice 

 for that purpose. The entire subject of diffusion, we may add, illus- 

 trates in a remarkable manner the importance of that perfect neutrality, 

 as a chemical agent, which has been shown to characterise water in the 

 preceding article on its chemical history. 



" The first, or difurirt, class of substances are marked by their 

 tendency to crystallise, either alone or in combination with 

 When in a state of solution they are held by the solvent with a certain 

 force, so as to affect the volatility of water by their presence. The 

 solution is generally free from viscosity, and is always sa;<id. 

 reactions are energetic, and quickly effected. This is the class of 

 crystalloid*." 



" The other class, of low di (fusibility, may be named cotttridt, as they 

 appear to be typified by animal gelatine. They have little, .; 

 tendency to crystallise, and they affect a vitreous structure. The 

 planes of the crystal, with its hardness and brittleness, are replaced in 

 the colloid by rounded outlines with more or less softness and tough- 

 ness of texture. Water of crystallisation is represented by water of 

 gelatination. Colloids are held in solution by a feeble power, and have 

 little effect on the volatility of the solvents. The solution of colloid* 

 has always a certain degree of viscosity, or gummiuess, when c 

 trated. They appear to be insipid, or wholly tasteless, unless whi-n ; hry 

 undergo decomposition upon the palate, and give rise to sapid crystal- 

 loids. They are united to water with a force of low intensity. 

 Although chemically inert in the ordinary sense, colloids possess a com- 

 parative activity of their own, arising out of their physical pn>|>ertieB. 

 While the rigidity of the crystalline structure shuts out external 

 impressions, the softness of the gelatinous colloid partakes of fluidity, 

 and enables the colloid to become a medium for liquid ditl'usion, like 

 water itself. The same penetrability appears to take the form of a 

 capacity for cementation in such colloids as can exist at a high tem- 

 perature. Hence a wide sensibility on the part of colloids to external 

 agents." 



" Another eminently characteristic quality of colloids is their muta- 

 bility. Their existence is a continued metastasis. A colloid may be 

 compared in this respect to water while existing liquid at a temperature 

 below its usual freezing point, or to a supersaturated saline solution. 

 The colloidal is, iu fact, a dynamical state of matter ; the crystolloidal 

 being the statical condition." 



" For the separation of unequally diffusive crystalloids from each 

 other, jar-diffusion was had recourse to. . . . The separation of a 

 crystalloid from a colloid is more properly effected by a combination of 

 diffusion with the [osmotic] action of a septum composed of an 

 insoluble colloidal material. . . . This separating action of the colloidal 

 septum is spoken of [in Mr. Graham's paper] as dialyii*." 



" fee at or near its melting point appears to be a colloidal substance, 

 and exhibits a resemblance to a firm ji-lly in elasticity, the tendency to 

 rend and to redintegrate on contact." Kegelation, according to this 

 view, is the form in which the property of redintegration, belonging to 

 all colloids, is exhibited by ice.* 



The truth of the view of the nature of ice, at or near its m 

 point, thus taken by Mr. Gruham, will require to be tested by . 

 means, by which it must be ascertained that, at those temperatures, it 

 really is not a crystallised body. A further verification may be ob- 

 tained by determining whether the alleged colloidal ice resists the 

 passage of electricity as crystalline ice is known to do, and what 

 changes the non-conducting power of the hitter undergoes, during the 

 reciprocal conversion of the crystalloid into the colloid state, until it 

 becomes the conducting power of liquid water. (Faraday, ' Exp. Res. 

 in Elect.' par. 403. ) Should its truth be established, Mr. Graham will 

 probably be admitted to have discovered the key to the explanation of 

 nil the conflicting statements and theories respecting the nature of 

 regelatiou and of the motion of glaciers. Ice, together with 

 iiliis. and perhaps all, will be both a colloid and a cry si 

 Tli.-tt which Dr. Faraday, in his recent experiments, found to 1m 

 flexible adhesion, will prove, in this case, to be the colloidal or vi 

 form of that substance (icc-ylaa, in fact; almost identical \\ith Mr. 

 Braylcy's homologue of that hitherto hyp- tlu ; 

 facts recorded by Mr. Graham, which will pi> 



while the rigid adhesion will be fan iloidal 



form; and the circumstances from which In- inferred that the i 

 has not in reality the properties of sticking and tenacity in short, 

 those of a viscous substance, will be found to arise from the constant 

 and rapid passage the metastasis of Graham of the colloid into the 

 crystalloid body. 



Regulation will consist of the passage, under small changes of pres- 

 sure and temperature, of cry- <ill"id i''e, and its re-c< 

 xion infci thi) I'uriiK "U " and " redintegration" of tho 

 cullciiii ; and thus Karnduj 's own interpretation 

 exporiiueiita and Professor Thomson's will be brought in 



* The Hov. Canon Uotrlry bad previously defined regelation as the " pro- 

 perl)' of paining from a disintegrated into a solid late." 



