432 



NATURE 



{Sept. 24, 1874 



a cyclone periodicity, if one exists, should be traceable in the 

 shipping intelligence. Now, from Table II., which gives the 

 published reports for 1856, i860, and 1867, it will be seen that 

 the number of storms and the damage sustained in 1S56 and 

 1867 were insignificant compared with the long list of hurricanes 

 and disasters in i860. 



Table III. gives as complete a list of liurricanes and storms 

 experienced in Mauritius as I have hitherto been enabled to 

 jirepare. The list comprises only such storms as from the violence 

 of the wind committed considerable damage. 



Table IV., which contains a list of Bourbon (Reunion) hurri- 

 canes and gales from 1733 to 1754, shows also the number of 

 hurricanes that occurred In the maximum and minimum sunspot 

 years. 



For the two islands the number of cyclones in the maxima 

 years was thirty-six, and for the minima years nineteen. This 

 result is favourable. 



It would appear also from M. Poey's researches, and from 

 investigations made at Mauritius in 1872, that the cyclones of the 

 West Indies are upon the whole subject to the same periodicity. 

 The rainfall for the twelve years under discussion is given in 

 Tables V. to IX. It thence appears from the rainfall at sixty- 

 seven stations that the maximum fall was in the years 1S59 to 

 1S62, and the minimum in the years 1S57, 1S5S, and 1864. We 

 thus find a certain degree of correspondence between the cyclone 

 and rainfall fluctuations ; and it is possible that if we had returns 

 from America tire corresjiondence would be nnich greater ; for 

 it would appear from researches by Mr. G. M. Dawson, that the 

 level of the American great lakes was considerably less in 1S67- 

 68 than in 1859-61. (The year 1867 has been almost the only 

 exception to the rule in Europe since the commencement of the 

 century, and as most of the stations are in that part of the world 

 the results for 1856 and 1857 are not so favourable as for previous 

 cycles). 



A large number of additional rainfall returns has been received 

 from Europe and other parts of the world, and the results, which 

 will be communicated in another report, afford fresh evidence of 

 a rainfall periodicity. 



(The paper was accompanied by several elaborate tables). 



SECTION B— Chemical Science 

 On some Op'mm Dcrivaliz-es, by Dr. C. R. A. Wright. — The 

 action of free chlorine on codeine is to produce higher polyme- 

 rides, especially tricodeine, from which again, by the action ol 

 hydrochloric acid, apocodeine is formed. This apocodeine may 

 be looked on as three molecules of codeine minus six molecules 

 of water. Narceine is feebly basic, but it has a strong attraction for 

 hydrochloric acid, giving rise to the crystallisable hydrochloride 

 CsHojNO,, ^ HCl. If the salt is dissolved in boiling water, 

 crystals are obtained containing six molecules of C^,3H2s,NOp plus 

 one molecule of IICl. Basic chlorides, probably not definite 

 compounds, have also been obtained. With excess of hydrochloric 

 acid at 100° the elements of water are removed from narceine, 

 and we get CjH^.-NOg. The hydrochloride of this base is 

 non-crystallisalDle. By the action of glacial acetic acid on 

 codeine there is jjroduced diacetyl codeine, C3iiH4|,2(C2H30) 

 N.^Og. Acetic acid acts in a similar way on moi-phine, a con- 

 siderable quantity of triacetyl moi-phine being also produced. 

 Acetic anhydride gives rise to the formation of an isomeric 

 diacetyl morphine. We have, therefore, — 



a diacetyl morphine . . . crystallisable 



and ;3 ,, .... non-crybtallisable. 



Butyric and benzoic acids give analogous compounds ; so also do 

 acetic acid and strychnine. The following general formulie for 

 the morphine and codeine salts are given : — 

 M + «I1X-«1I.,0, 

 C ■*• nB.^-ni\oO, 

 when HX = a monobasic acid. 



On a Phenomenon noticed on 'horing a Well, by L)r. Andrews. 

 — The author described a remarkable jet of almost pure marsh- 

 gas, obtained on boring a well near Belfast. The borings first 

 descended through about 33 ft. of silt, and then reached a gravelly 

 deposit 7 it. in thickness, interspersed with organic iiSris. It 

 was from this deposit that the marsh-gas was evolved. 



Reattion of Ilyiirogen, PcroxiJ,; iSr-c, by Mr. Fairley.— The 

 author believes that he has succeeded in preparing hypocldorous 

 acid according to the equation H.jO.j + CL = 2IICIO. By the 

 action of hydrogen peroxide on bleaching powder, and on other 

 hypochlorites, oxygen is evolved ; thus, with potassium hypo- 



chlorite, KCIO -f H.O, = KCl -(- H„0 -t- O2. Chloric acid 

 has no action on hydrogen peroxide ; neither has sulphuretted 

 hydrogen in the absence of air. By the action of ozone on hypo- 

 chlorous acid there seems to be produced perchloric acid. 



On t/w Gt'iural Rqnaiiois of Chemical Decomposition^ by Prof. 

 Clifford, F. R. .S. — This paper was also read before Section A. 

 The author thinks that chemical equations may he brought under 

 a general formula. Thus, H; -f CU = 2HCI. If we assume that 

 there is a s'ructure common to the hydrogen and the chlorine 

 atoms, also a structure confined to the hydrogen and likewise a 

 structure confined to the chlorine atoms, we may represent this 

 equation thus : XYY -)- XZZ = aXYZ, when X represents the 

 common structure and Y and Z the structures which are confined 

 to hydrogen and chlorine respectively. So 2H2 -|- 0„ = 2H.,0 

 may be represented thus : 2XY + XXZZ = 2XXYZ. These 

 equations involve no hypotheses, because the fundamental facts 

 of the molecular theory are now firmly established. Reasoning 

 from these and similar equations, the author deduces the result 

 that the ordinary equations of chemistry, such as those just 

 stated, are expressive of facts, and that the hydrogen molecule 

 really consists of two equal atoms. 



On the presence of Cyanogen in Commercial Bromine, and a 

 means of detecting it, by Dr. T. L. Phipson. — The author states 

 that commercial bromine often contains cyanogen ; by adding an 

 equal weight of iron filings and four to five times its weight of 

 water to the bromine, stirring, filtering, and allowing the filtrate 

 to remain for twenty-four hours in a closed bottle, a precipitate of 

 Prussian blue is thrown down if cyanogen is present. 



On a Sesqui-snlphide of Iron, by Dr. Phipson. — The author 

 describes a greenish black salt having the composition FeoS^. 

 This salt is produced by precipitating a ferric salt by means of 

 ammonium sulphide in the presence of a free chlorite or hypo- 

 chlorite. The salt is soluble in hot water, also in ammonia, 

 giving an emerald green liquid. 



On the Chlor- Bromides and Brom-Iodides of the Oltfnes, by 

 Prof Maxwell Simpson, F.R.S. — The author described various 

 substances obtained by acting on ethylene, &c., with iodine chlo- 

 ride, with bromine chloride, with bromine iodide, &c. In the 

 case of ethylene the substance CjH^Brl, C.jH^CII, and 

 CnlljClBr, were described. These bodies may also be obtained 

 by agitating the chloride bromide or iodide of ethylene with a 

 solution of iodine or bromine chloride : thus, C.^H^Br., -f BrI =: 

 CalljBrI + Br.„ The reaction C.^H^Cy.^ + BiCy- CaHjCyBr-i- 

 Cy^ would not take place ; indeed, the author was totally unable 

 to prepare the brom- or iodide cyanide corresponding to the salts 

 ju;t mentioned. 



On an Aspirator, by Dr. Andrews, F.R.S., and On another 

 form of Aspirator, by Prof. DelH's, could not well be understood 

 without drawings. 



SECTION C— Geology 



'J'he Geological Structure of the Tyrone Coal-field. — Mr. Hard- 

 man, after describing the position of these beds, remarked that 

 lue carboniferous rocks of this district appear to resemble some- 

 what those of the northern counties of England. The coal- 

 bearing beds are true coal measures. The underlying limestone 

 is split up by numerous sedimentary beds, and, on the wl ole, 

 agrees with the Ballycastle coal-field, which beds Prof. Hull 

 assigns to the same horizon with tho c of the Scotch coal 

 measures. The author referred in detail to the thickness and 

 jiosition of the beds. With reference to the Diingaimon coal- 

 field, which extends from near Dungannon to beyond Coalisland, 

 lie lemarked that though small in area it was rich in coal seams, 

 jiossessing twenty-four coal-beds, of which at least thirteen were 

 workable. They are highly bituminous, and two of the beds 

 contain valuable seams of cannel coal. The chemical analyses 

 show that these coals are valuable, possessing from 37^5 to 47 

 per cent, of volatile matter for gas manufacture. In the upper 

 measures we have valuable deposits of lire-clay, which are exten- 

 .sively used for the manufacture of bricks and tiles. The iron- 

 stones are not sufiiciently abundant to he worked, yet they yield 

 as much ns 217 to 35 '5 per cent, of metallic iron. There must 

 be from 30,000,000 to 40,000,000 tons of coal yet untouched. If 

 we count the smaller beds we shall have at least 9,000,0x30 more. 

 The coal-field is bounded on the north-west by a large fault, 

 which brings down the cool measures on the south against the 

 calp and lower limestone. It must have a downward throw of 

 2,000 feet. Northwards, the limestone is covered by trias, 



