262 



NA TURE 



\_yan, 14, 1 886 



known to me. It is this varied and widely diffused effort which 

 has rendered possible the realisation of the practical results 

 which I have the gratification to record, and all the members of 

 this Society must equally join in the common satisfaction in the 

 measure of success which has been achieved. 



Six years back, when the subject was discussed in this hall, 

 there were probably not a few who viewed the proj^ositions then 

 submitted as merely fanciful theories. Others, who did not 

 refuse to recogni e their bearing, entertained t!i ' feeling tliat 

 many grave difficulties pre=ented tliemselves to interfere witli any 

 successful attempt to reform or mo:lify usages so ancient as the 

 computation of time. But the Institute, as a body, was hopeful. 

 The action taken by the Council to extend the field of discii ^^ion 

 and awaken the attention of foreign communities, evinced con- 

 fidence, and we may now ask, was this confidence justified? 

 What are the facts to-day? Twelve months have passed since 

 an important change in the notation of railway time was made 

 with general approv.al throughout the length and breadth of 

 North America; a revolution in the usages of 60,000,000 of 

 people has been silently effected and with scarcely a trace that 

 it has happened. That proceeding has been followed by events 

 of equal importance. On October I last a body of accredited 

 delegates from the different nations, on the invitation of the 

 President of the United States, met in Conference to con-ider 

 the problem first submitted to the world by this Institute. The 

 delegates were the representatives of 25 civilised nations. The 

 Conference continued during the whol' month of October, and, 

 as a body, they came to conclusions affecting all peoples living 

 under our theories of civihsation. 



It was early understood that a determination with respect to 

 Universal Time was not possible without the general recognition 

 of a Prime Meridian. Hence the importance attached to its 

 choice, that it should be universally accepted. 



SOCIETIES AND ACADEMIES 

 London 



Royal Society, December 10, 18S5 — Abstract of a Paper 

 on "Preliminary Results of a Comparison of Certain Simul- 

 taneous Fluctuations of the Declination at Kew and at 

 Stonyhurst during 1SS3-84, as recorded by the Magnetographs." 

 By the Rev. S. J. Perry, F.R.S., and Profi B. Stewart, F.R.S. 



The authors remark that such fluctuations almost always 

 occur as couplets or groups of couplets ; a couplet meaning first 

 an ascent and then a descent, or the reverse. In their opinion 

 this duality and the other facts of their paper can best be ex- 

 plained by supposing that a recorded magnetic fluctuation is 

 the joint result of two causes : the one of these being a true mag- 

 netic change, and the other a secondary current ciused by this 

 change. The secondary current \^ ould probably appear as an 

 earth-current. Its maximum strength would depend on the 

 maximum rate of magnetic change, but as this last element is 

 quite unknown, we may perhaps suppose that this maximum 

 strength will be practically proportional to the mean rate of 

 magnetic change. 



On this supjiosition the authors suggest the following formula 

 as capable of being used as a preliminary working hypothesis. 



Let A' denote the observed Kew change, and /& the true mag- 

 netic change at Kew, also let / represent the duration ; then 



A' = ^( I :f - j where a is a constant. Also if .V represent the 



observed simultaneous Stonyhurst cliange, then .?—/(•( ,8 q: 2 j , 



the sign - being applicable to the first limb, and the sign -h 

 to theisecond limb of the couplet. 



It follows from this that - = ^, or, in other words. 



T 7 



that the ratio between the Kew and Stonyhurst observed disturb- 

 ances will be a function of the duration, quite apart from all theo- 

 retical considerations, which can only in the meantime be re- 

 garded as pointing out a method of treatment. The authors 

 then practically discuss their results, and have obtained the 

 following preliminary conclusions : — 



.y 



K 

 greater than unity. 



(l) 5' is always greater tha 



(2) This ratio appears 10 depend in some way on the duration 

 of the disturliance ; 



(3) But not, as far as can be seen at present, upon its 

 magnitude. 



Finally, they hope to make a more extended investigation of 

 the subject, giing over a greater number of years, and perhaps 

 adding to their methods of treatment. 



" On the Limited Hydration of Ammonium Carbamate." By 

 H. J. H. Fenton. 



The hydration of ammonium carbamate affords an example of 

 a chemical action of the simplest type, namely, the direct union 

 of two simpler molecules to form one more complex — 

 CO(NH.,)(ONHJ -I- OH2 = CO(ONH,)i,- 

 There are but few actions of this type which can be investigated 

 when all the substances concerned are in the liquid state, and 

 all extraneous matter absent. 



In a former paper it w.is shown that ammonium carbamate, 

 when acted upon by sodium hypochlorite in presence of sodium 

 hydroxide, yields one half of its nitrogen in the free state, the 

 other half remaining in the form of sodium carbamate — 

 2CO(NH„)(ONH.,) -H"3NaC10 -f zNaOH = 2C0(NH„)(0Na) 

 • -f 3NaCI -(- 5OH., -i- N„. 



Sodium hypohromire at once decomposes sodium carbamate, 

 yielding the nitrogen in the free state. This, in fact, is claimed 

 as a specific reaction for carbamates, since no other substance 

 yet investigated will yield free nitrogen by action of a hypo- 

 bromite after the completed action of a hypochlorite. 



Based upon this reaction, then, we have a direct and simple 

 method of determining the amount of carbamate existing in a 

 solution at any given time. 



Experiments were conducted with a view of examining the 

 influences of time, mass, and temperature upon the hydration of 

 ammonium carbamate, and also tlie reverse action, namely, the 

 dehydration of normal ammonium carbonate into ammonium 

 carbamate. The hydration is expressed by the ratio — 

 molecules of water assimilated 

 molecules of carbamate taken 



(1) Influence oi Time. — Solutions of ammonium carbamate of 

 different strengths were examined at stated intervals. In all 

 cases the action proceeds rapidly at first, becomes progressively 

 slower, and finally reaches a limit short of complete hydration. 



The time required to reach a determinate state of hydration is 

 less as the relative number of water-molecules is greater. 



(2) Influence of Mass.- — The hydration is shown to be a 

 function of the number of water molecules present. As far as 

 the action could be legitimately studied, the minimum hydration 

 corresponded to the case in which the substances are present in 

 equal molecular proportions. 



(3) Influence of Temperature. — The hydration is in all cases 

 less, as the temperature is lower. Probably at a sufficiently low 

 temperature tne hydration would be practically nil wlien the 

 substances are present in equal molecular proportions — ;.'■. 

 ammonium carbamate and water would practically not combine 

 at all. 



(4) Dehydration of Normal Ammonium Carbonate. — It was 

 shown that this salt undergoes dehydration in solution, be- 

 coming in part converted into carbamate. The dehydration is 

 greater, as the relative number of water-molecules is less. It 

 seems not unlikely that if the same relative number of molecules 

 could be started with, the same equilibrium state between car- 

 bamate, carbonate, and water, would be arrived at for the same 

 temperature, whether ammonium carbamate or normal am- 

 monium, carbonate were initially taken. 



Since there is a tendency for normal ammonium carbonate to 

 become in part dehydrated in aqueous solution, and for the 

 system to come to a state of equilibrium where the carbamate 

 and carbonate co-exist, it seems probable that the hydrolysis of 

 urea under the action of ferments may be less simple than is 

 usually represented. The author proposes to attack theprobleur 

 by a method based on the actions of sodium hypochlorite and 

 hypobromite, by means of wiiich it is possible to delect, and 

 quantitatively estimate, urea, carbamic acid, and ammonia, when 

 all present in the same solution. A preliminary trial of the 

 method gave satisfactory results. 



Geological Society, December 16, 18S5. — W. Carruthers, 

 Vice-President, in the chair. — Charles John Alford, Samuel 

 Blows, James Warne Chenhall, William Farnworth, Paget 



