Sept. 30, 1875] 



NATURE 



481 



of this single stem is not to be assigned to either chance 

 or to chemico-physical, but to an " Entwickelungs-gesetz " 

 yet to be discovered. This, we confess, is to us a disap- 

 pointing termination to a clever and spirited essay. 

 Surely Dr. Dohrn would not expect a scientific man to 

 understand by the word " chance " anything but a peri- 

 phrasis for the operation of hidden cause. And what can 

 he expect any law of development to be, if not an expres- 

 sion of the operation of chemico-physical causes ? 



As to the original form under which life made its first 

 appearance, Dr. Dohrn's words would almost lead to the 

 impression that he believes in the creation of a " type- 

 form ■' something like the Cherubim, with an account of 

 which Archdeacon Freeman favoured Section D of the 

 British Association when it met at Exeter in 1869. His 

 language is, however, sufficiently vague to warrant the 

 supposition that, as an orthodox physical philosopher, he 

 holds the doctrine of the evolution of organic forms sub- 

 ject to the larger doctrine of general evolution, and conse- 

 quently we may suppose that he would hold that the 

 single stem which has blossomed in man, and from which 

 all other forms have descended by retrograde develop- 

 ment, did take its origin from simple protoplasm, which 

 had naturally been evolved from carbon compounds. If 

 the animal pedigree did originate from these very simple 

 beginnings, we suppose Dr. Dohrn would say that all 

 trace of them is gone, what is simple now in the way of 

 organisms is not the simplicity of the original stock, but 

 a simplicity attained by degeneration. We do not see 

 any reason to accept this hypothesis of universal degra- 

 dation (man alone being excepted from its influence), any 

 more than we can see reason to accept the competing 

 hypothesis of universal progress. We are very strongly 

 inclined to think that neither hypothesis can have the 

 whole field to itself. We should expect to find in some 

 directions progress, in others retrogression. 



The extent to which each of these processes has gone 

 on in past ages in connection with the family history of 

 the animal kingdom is the great problem for zoological 

 research, E, R L, 



excess of aqua regia without undergoing any loss by 

 volatilisation. 



When hydrated zinc chloride containing a trace of the 

 new substance is heated to the point when zinc oxychlo- 

 ridc begins to form, the gallium remains in an insoluble 

 condition, possibly as oxychloride. 



The quantity of the substance procured was too small 

 to attempt its isolation. Some drops of zinc chloride 

 solution in which the new metal had been concentrated 

 were examined spectroscopically by the electric spark. The 

 spectrum is composed chiefly of a violet line about wave- 

 length 417, and a feeble line about 404. 



In his communication to the French Academy, the 

 author states that he obtained the first indications of the 

 new metal on Friday, Aug. 27. It is to be hoped that a 

 good supply of the mineral will be procurable, so that the 

 new element may be isolated, its atomic weight deter- 

 mined, and its reactions studied in detail. This now 

 makes the fifth terrestrial element which the spectro- 

 scope has been instrumental in bringing to light. 



R. Meldola 



THE NEW METAL GALLIUM 



THE discovery, by M. Lecoq de Boisbaudran, of a sup- 

 posed new element in a blende from the Pierrefite 

 mine in the Argeles Valley, Pyrenees, was made known 

 in our " Notes " of last week. This element, which the 

 discoverer proposes to name Gallium, has revealed itself 

 by the following chemical reactions : — 



The oxide, or possibly suboxide, is precipitated by 

 metallic zinc from a solution containing chlorides and 

 sulphates. 



In a mixture of the chlorides of the new metal and of 

 zirc, ammonia throws down the new element first if added 

 in a quantity insufficient to precipitate the whole of the 

 metals present. Nearly the whole of the gallium is thus 

 thrown down in the first fraction. 



Under conditions competent to peroxidise the new 

 metal, the oxide is soluble in excess of ammonia. 



Ammonium sulphydrate produces a precipitate insoluble 

 in an excess of the reagent. The sulphide appears to be 

 white. 



Sulphuretted hydrogen produces a precipitate in pre- 

 sence of ammonium acetate and excess of acetic acid. In 

 presence of zinc salts the new substance concentrates 

 itself in the sulphides first deposited, but six fractional 

 precipitations were requisite to remove the greatest part 

 of the zinc sulphide. In presence of hydrochloric acid 

 no precipitate is formed. 



The oxide, like that of zinc, dissolves in excess of 

 ammonium carbonate. 



The salts of gallium are readily precipitated in the cold 

 by barium carbonate. 



The chloride may be frequently evaporated with great 



UNPUBLISHED LETTERS OF GILBERT 

 WHITE 



AT the meeting of the Norfolk and Norwich Natu- 

 ralists' Society, held on the 28th inst., the secretary 

 read an interesting series of ten unpublished letters, 

 written by Gilbert White, of Selborne, to Robert 

 Marsham, F.R.S., of Stratton Strawless, Norfolk, and 

 communicated by the Rev. H. P. Marsham, great-grand- 

 son of the latter. The letters, which are dated between 

 August 13, 1790, and June 15, 1793, are excellent exam- 

 ples of Gilbert White's delightfully discursive style, their 

 contents being of a very varied nature, Mr. Marsham, 

 to whom they were addressed, was a great planter, and 

 communicated his experiments on growing trees to the 

 Royal Society ; the beauty and great size of the timber 

 at Stratton bear testimony at the present day to his 

 judgment and successful treatment. As might be 

 expected, under these circumstances, a Urge por- 

 tion of the correspondence is devoted to lorest-trees, 

 the love for which was shared in an almost equal 

 degree by both correspondents. The " Indications of 

 Spring," of which Mr, Marsham left such a remarkable 

 register, and which have been continued by his family, 

 with one slight interruption, from the year 1736 to the 

 present time (see " Philosophical Transactions " for 1789, 

 and the "Transactions" of this Society for 1874-5), of 

 course form an annual topic, as well as the rainfall ; but 

 perhaps the most valuable part of the correspondence is 

 the gossip about birds, some of which is of very great 

 interest. On the 30th October, 1792, Marsham writes to 

 White : " My man has just shot me a bird which was 

 flying about my house ; I am confident I have never seen 

 its likeness before." On reference to his Willoughby, he 

 declares it to be " the Wall-creeper, or Spider-catcher," 

 and a description, endorsed by him on one of White's 

 letters, as well as a manuscript note in his copy 

 of Willoughby's " Ornithology," still in the posses- 

 sion of the Marsham family, places it beyond doubt 

 that the bird was a veritable Tichodronia muraria. 

 White, after saying he is persuaded that the bird is the 

 " very Certhia muraria," continues : " You will have the 

 satisfaction of introducing a new bird of which future 

 ornithologists will say, ' Found at Stratton, in Norfolk, by 

 that painful and accurate naturalist, Robert Marsham, 

 Esq.,' "—a prophesy which, after an interval of eighty-two 

 years, will at length be fulfilled. Nearly a whole letter is 

 devoted to an extract from an unpublished " Natural 

 History of Gibraltar," by Gilbert White's brother, the 

 Rev. John White, who resided many years on the 

 " Rock." By this it is shown that John White, who went 

 to reside there in 1756, soon discovered the Crag Swallow 



