Oct. 8, 1874] 



NATURE 



473 



action exerted by the dialyser in producing the compounds. The 

 author concludes that the following points have been probably 

 established by his experiments: — (i) The existence of definite 

 compounds of albumin with the acids in simple molecular ratios 

 (the jiruljabic formula of the nitric acid compound may be given 

 bywayofillustration—C-JIii,,N,j,S05,,2llNO:,). (2) The applica- 

 bility of dialysis to the ready and accurate preparation of these 

 compounds. (3) Probable correctness of the formula of 

 Lieberkiilin, Loew, and Liebig for albumin. — On a simple method 

 of estimating urea m urine, by Dr. W. J. Russell and S. H. 

 West. The authors make use of the well-known action of hypo- 

 chlorites and hypobromites upon urea : — 



CO(NH„), -h 3HCIO = CO. + 3HCI + 2H2O -f N.. 

 The most advantageous solution for this purpose is formed by 

 dissolving 100 grms. of caustic soda in 250 c.c. of water, and 

 adding 25 c.c. of bromine. A measured quantity of urine is in- 

 troduced into a bulb-tube of particular form, and then allowed 

 to mix vi'ith excess of the hypobromite solution. The reaction is 

 complete in from ten to fifteen minutes in the cold, but on 

 warming is complete in five minutes. The apparatus is so con- 

 structed as to permit the collecting of the evolved nitrogen in a 

 tube which is graduated in such a manner that the amount of gas 

 read off gives at once the percentage of urea in the urine em- 

 ployed. A remarkable fact observed by the authors is that in 

 the reaction between urea and the hypobromite there is invariably 

 eight per cent, less nitrogen evolved than that required by theory. 

 With uric acid 35 P^'' cc"'' of the nitrogen is suppressed, with 

 hippuric acid S2A percent., and with creatinine 25 percent. — 

 The concluding paper is on Dendritic spots m paper, by Huskis- 

 son Adrian. 



The Scottish Naturalist lor October contains the following 



articles : — On the Salmonidre of the Eden, Fife, by P. Walker, 



F.G.S.E. — Notes on the entomology of Shetland, by the Rev. 



'J. Blackburn and C. E. Lilley. — Concerning aquaria, by Dr. 



' Peter White. — Tenthredinidae in Rannoch, by P. Cameron. — 



Notes on Lcpidoptera in Kirkcudbrightshire, by W. D. Robinson 



' Douglas. — The occurrence of rare birds in the Carse of Gowrie, 



j by Col. Drummond Hay. — Several articles on the fungi of 



I Scotland, and a continuation of the lists of .Scottish insects, by 



F. Buchanan White, M.D., and D. Sharp, M.B. 

 \ The Bnlhiin de la Socictc d'Accliiiialalion r/t- /"a/w for June 

 I opens with a paper by M. Ch. le Doux, on the yield of the co- 

 coons of the new silkworm Attaciis niirota, and on the best mode 

 of winding the cocoons which are pierced by the moth on its 

 escape, or left unfinished by the silkworm. — M. P. Chappellier 

 gives an interesting account of the growth and preparation of 

 saffron, with special reference to the production of new species 

 ( of crocus and other saffron yielding plants in France. — The East 

 Indian possessions of Holland, Java, Sumatia, Borneo, the 

 Moluccas, and other islands, are the subject of a paper by M. 

 I E. Prillieux, who gives a valuable list of tl'.eir principal produc- 

 I tions, industrial and otherwise. This list includes no less than 

 247 timber-producing plants grown in the East Indies. — Among 

 fishery questions perhaps no subject is of more importance than 

 the effect produced by the use of fixed engines. Contributions 

 to the literature on this point are made by M. Renibaud in a 

 letter aildressed to the Minister of Jtarine, and by Dr. Turrel, 

 delegate of the society at Toulon, — M. Delidon continues his 

 researches on the change of colour in the silk produced by silk- 

 worms, caused by a change of food. — M. Kemmerer, the inventor 

 of cemented tiles for catching oyster-spat, announces that he has 

 relinquished his patent rights in the invention which has been 

 so successfully adopted by oyster-culturists. — The Minutes of the 

 monthly meeting of the society, detailing the various experiments 

 made by its members, are very interesting, including observations 

 on many diverse subjects. — The Agricultural Society of France 

 has offered a prize of 1,000 francs each for the best method of 

 artificial irrigation, for the best means of destroying the PhyUoxcra 

 vastatrix, for the best economical means of utilising the beetroot 

 and its products, lor the best horse-broeding establishment in 

 Finistere, Cntcs-du-Nord, Morbihan, lUe-et-Villaine, and Loire 

 Inferieure, and for the educational establishment which shall have 

 taken the best means to instruct in agriculture and horticulture. 



Zdtschrift dcr (Esterrcichischen Gcsellschaft fiir Mdeoiologic, 

 Sept. I . — In a former number of this periodical an instrament called 

 the nephoscope was described by Herr Braun, intended to serve 

 for measurement of the direction and apparent velocity of clouds. 

 He has now made an addition to the nephoscope, by which the 

 absolute height of clouds may be determined without any calcula- 



tion, and thence also their absolute velocity. Such an instru- 

 ment has been wanting in meteorology, and will certainly be 

 useful. Of course the cloud chosen for measurement must be 

 isolated and not very high, and the place of operation must be 

 elevated and so placed as to command a view of the cloud's 

 shadow. It is the height of the cloud above its shadow, not 

 above the place of observation, which is obtained. Tlie old 

 method may still be followed with the nephoscope, but it is more 

 laborious. The instrument is minutely described with reference 

 to an annexed woodcut. — Among the Kleinere Mitthcilungeii we 

 have a notice of Prof. Lommel's book, " Wind und Wetter." 

 His explanation of the cun'es of storms issuing from the region 

 of trade winds is somewhat as follows : — The rotation of the 

 cyclone being in the N.E. trade vrind from N. through W. and 

 S. to E., the N.E. trade wind opposes and retards the S.E. 

 portion, but accelerates the N.W. portion of the whirl. Thus 

 the pressure mil be least in the N.W., greatest in the S.E. 

 quarter, and progi-ess will be made towards the N.W. Arrived 

 in the region of variable winds, the course mil be changed accor- 

 ding to the direction of the prevailing wind. Supposing a storm 

 to be on the western coasts of Europe, and the most common 

 wind, S.W., to be blowing, the direction of progress will be E. 

 orE.S.E., and this is actually the course commonly taken by 

 European storms. 



Mciiioyie della Societa degli Spettroscopisli Italiani, July. — This 

 number contains an announcement of the death of Paolo Rosa at 

 Rome on the nth of July, and a short statement of his scientific 

 labours ; it also contains a letter from P. Rosa on the connection 

 of solar activity and rainfall, and a paper by the same author on 

 the identity of photospheric and magnetic phenomena in connection 

 with the proper motion of the sun. Taljles are given showing a 

 corresponding variation of the magnetic variation with the changes 

 in the solar diameter, there being an 11 -year period of both, and 

 also a secular period of 665 years. Secchi writes that the spectrum 

 of Coggia's comet corresponded with that of a hydrocarbon, 

 and that the continuous spectrum observed therewith was due 

 to reflected sunlight, since it disappeared on interposing a Nicol's 

 prism. Prof. Bredichin fi.xes the lines at 5633, 5164, and 4742 of 

 Angstrom's scale ; and Tacchini at 6770, 5620, 5 1 10, and 4800 ; 

 the longest w.is 5620, and the brightest 5110. The chromosphere 

 as seen in January last is shown in a drawing by Tacchini, and 

 he adds that he has seen the chromosphere steadily at an altitude 

 of 3° from the horizon, and when the limb of the sun was very 

 unsteady in a simple telescope. — Tacchini sends a note that four 

 bolides travelling together entered our atmosphere on the 27th 

 of July, the position and drawing is given ; they were seen for 40 

 seconds. — A number of drawings of Coggia's comet are sent by 

 Tacchini, with a descriptive statement. Wright adds a note that 

 the comet's light was polarised. 



Journal de Physique, tome iii., Nos. 2g, 30. — In these two 

 numbers is an article by M. Berthelot on the principles of Thermo- 

 chemistry. The study of the evolution of heat in chemical 

 combinations is a new branch of science belonging partly to 

 physics and partly to chemistry, and the number of facts already 

 observed is sufficiently numerous to indicate certain laws which 

 M. Berthelot proceeds to set forth. It is, he premises, admitted 

 that in a chemical combination the molecules hit sharply one 

 against another and give off heat, just as when a hammer strikes 

 a bar of iron. From a study of the relations between the amount 

 of heat evolved and the amount of work done, it is possible to 

 establish some theorems of Thermo-chemistry. i . First prin- 

 ciple. The amount of heat given off in any reaction is a measure 

 of the chemical or physical work done in that reaction. Several 

 examples are given. 35^5 grs. of chlorine unite with i gr. of 

 hydrogen and form hydrochloric acid, giving off 22 calories. 

 The compound occupies the same volume as its component parts. 

 Here the physical work is nil xad. the chemical is 22 E (E being 

 the mechanical equivalent of heat.) Again, 8 grs. of O unite 

 with I of H to form water. At ordinary temperatures the heat 

 evolved is 34 '5 calories. But there is a change from gas to 

 liquid. Part of the work is chemical, part physical. It is .shown, 

 then, that the temperature affects the amount of heat evolved ; 

 this is due to the physical work of exterior pressure. All com- 

 putations should, when possible, be made with both the com- 

 ponents and the compound in the state of gas. This is not always 

 possible ; hence the importance of the second principle. 2, If a 

 system of simple or compound bodies taken in certain conditions 

 lead to physical or chemical changes which bring about a fresh 

 state without giving rise to any mechanical result, then the heat 

 given off or absorbed by these changes depends entirely on the 



