5jS 



NA TURE 



[October 4, 1S94 



on Roberts' photograph (1SS9); the circular spots are stars, 

 recognisable in the drawini;. Unless this part of the Trouvelot 

 drawing — the excellence of which is stated by Dr. Roberts him- 

 self — be ver)' incorrect, the nebula would seem to have turned 

 about 15° from left to right. The globular nebula (M. 32^ to the 

 other side of M. 31, seems also to have slightly shifted its 

 pos'tion. 



Evidence of the reality of such changes is of course only 

 obtainable by comparing three or more photographs taken at 

 comparatively wide intervals. In the meantime, this short notice 

 in Natl RE may call the attention of photo-astronomers to this 

 interesting point. 



l>ordrecht, September 14. C. Easton. 



On the Identification of Habitual Criminals by 

 Finger-Prints. 



A PARLIAMENTARY Blue Book on "The Identification of 

 Habitual Criminals." which has recently been issued, reports on 

 The Fiuger-Print System, stated to have been " first suggested. 

 and tosomeex'ent applied practically, hy Sir William Ilerschel." 



The chairman of the committee appointed by Mr. .Xsquith, 

 whose report contains the above statement, refers me for his 

 evidence on this point to Mr. Gallon's work on "Finger-Prints" 

 (Macmillan and Co., 1S92). 



My "careful study" of the subject is mentioned there, and 

 an article of mine in Nature, October 2S, 1S80 (vol. xxii. p. 

 605), is referred to. It i' correctly indexed in the " Index 

 Medicus " for the year, published in 18S1, although Mr. Galton 

 spells and indexes my name incorrectly. That article, I 

 believe, is absolutely the first notice of the subject contained 

 in English literature, and the conclusion I reached therein was 

 that the patterns of the skin-furrows, with their distinctive 

 loops, whorls, and lines, breaking and blending like the junc- 

 tions in a radway map, were capable of being readily used as 

 a reliable and permanent basis for the " scientific identification 

 of criminals." I conclude my paper with the statement that 

 " There can be no doubt as to the advantage of having, besides 

 their photographs, a nature-copy of the for-ever unchangeable 

 fineer-furrows of important criminals." 



Sir William Herschel wrote in Napure, November 25 of 

 the same year, alleging that he had "been taking sign-manuals 

 hy means of finger-marks for now more than twenty years." 

 It doe; not yet appear that anything had been published on the 

 subject by that gentleman till my contribution called forth his 

 letter a month afterwards. The collections made by .Sir W. 

 Herschel were recently placed in Mr. Galton's hands, and that 

 writer states that " they refer to one or more fingers, and in a 

 few instances to the whole hand, of fifteen different persons." 

 (" Finger-prints," p. 9.) 



It is not staled how many of these had been imprinted prior 

 to my first calling attention to the subject. At present it 

 would «eem that Sir. W. Ilerschel had not accumulated the 

 impressions at a more rapid rate than that of one person in 

 two years I .^s we are informed in the letter to Nature, 

 referred to above, that the identification of pensioners had 

 been secured in this way, 'hat the method was in use in ail the 

 registration offices of the district, and that "on commitment to 

 gaol, each prisoner had to sign with his finger," I should have 

 expected that a somewhat more extensive collection might 

 have been secured. As priority of publication is generally hel.l 

 10 count for something, and as I knew absolutely nothing of 

 Sir W. Herschel's studies, nor ever heard of anyone in India 

 who did, some little evidence on the point of priority would 

 be nf interest even now. 



Mr. Galton says, of Sir W. Ilerschel, "He informs me that he 

 «ubmilted, in 1S77, a report in semi-oflTicial form to the 

 Inspector-General of Gaols, asking to be allowed to extend the 

 procesi : but no result followed." (p. 28.) A copy of that 

 »emi-oflicial report would go far to settle the question of 

 priority, as its date is nearly two years previous to my having 

 noticed the finger-furrows. No reference to them w.as then to be 

 found in any ana'omical work that I could find access to, ami 

 no writer on identification had ever thought of ihem a< a means 

 to that end. My inlcrett, like that of Putkcnje, arose from a 

 tpeci.il jiudy of the ienie of touch, ami I was then lecturing to 

 medical students on the " Physiology of the Sensc«." Having 

 myopic eyes which en.ible me to write with ease the Lord's 

 Prayer three limes in the space of a sixpence, I soon noticed 



NO. I 30 1, VOL. 50] 



the unique patterns which the papillary ridges formed. I 

 happened to be studying the prehistoric pottery of Japan at the 

 same time, and became interested in obierving that these 

 patterns were similar, but, I thought, finer and more slender 

 than those of the present day. which pointed, I conjectured, to 

 the employment of children in early fictile ait. However th.-.t 

 may be, my knowledge of the subject had a natural and 

 inilependent genesis. 



The subject of identification by this means has been brought 

 under the notice of the authorities on criminal matters of 

 different countrie^ by me from time to time, and some vears 

 before Mr. Galton's work was published, Scitland Yard 

 placed one of its most enlightened officers in communication with 

 me on the subject. Inspector Tunbridge studied the suhject with 

 me during a forenoon. Even in iSSo, I prepared copper-plate 

 outlines of the two hands, accompanied wiih instructions as to 

 obtaining finger-prints, and some two chief points on the palm, 

 where the rugx are characteristic. Sir W. Herschel's letter 

 mentions prints of one finger only as being obtained from 

 prisoners on commitment. On page 79 of the lilue Hook 

 mentioned above, " Instructions for taking Finger-Prints " are 

 given for the benefit of jirison warders, and the ten fingers are 

 to l)e printed from, .as I have advocated. I may add that I 

 have not the slightest wish to diminish the credit that may be 

 due to Sir W. Her-chel. What I wish to point out is that his 

 claim ought to he brought out a little more clearly than has yet 

 been done, either by himself or by Mr. Gaiton. What pre- 

 cisely did he do, and when? Henry Faulds. 



The Tetrahedral Carbon Atotn 



VotR reviewer, in his notice of my " Elementary Lessons in 

 Organic Chemistry," takes exception to the statement that the 

 carbon atom has been hypothetically regarded as tetrahedral in 

 shape ; he is presumably unacquainted with the criticisms of 

 Lossen (Fdidile 20, p. 3306) on Wislicenus's memoir, with 

 Wislicenus's reply' i/leru/ite 21, p. 581), as well as with the 

 pamphlet r^f Wunderlich (" Configuration organischer 

 Molekule," Wurzburg, 1SS6) : he need not, however, search 

 " the whole range of stereo-chemical literature " for references 

 of this kind, as there is in the " Ilandbuch " of V. Meyer and 

 Jacobson, pp. 433-436, a tolerably full discussion as to the 

 ultimate cause of stereo-isomerism in carbon compounds, wheic 

 it is stated (p. 434) that "the carbon atom may be regarded 

 as a mass of finite extension in space, of any shape, with foui 

 points on its surface corresponding to the corners of a regular 

 tetrahedron as the units of affinity." 



Most writirs on stereo-chemical subjects prefer to speak of 

 the tetrahedral arrangement in space of the four valencies of 

 the carbon atom, rather than of the tetrahedral shape of the 

 carbon atom itself; but if the "valencies" are sufl'icicntly 

 material to have a definite position in space, they may fairly 

 be regarded as parts of the carbon atom, which then become^ 

 of finite size, und /o r t/ie fiirf'oscs <y' ,c/;;fo-c/;t-m/V/rr essentially 

 tetrahedral in ^hape. 1 his form of statement has the meiitof 

 simplicity, and is in itself less objectionable than the idea of 

 " valencies " tlirected towards the corners of a tetrahedron ; at 

 the same time, I freely admit that the statement errs on the side 

 of excessive simplicity, and is not what would be adopted 

 before a cl.iss of honours students. 



It is possible to connect the facts of stereo-isomerism to some 

 extent by a series of separate propositions, and at the same time 

 10 .avoid any reference to the distribution of the "valencies'' 

 in space, or to the finite size of the carbon atom ; one of these 

 propositions would be that " two carbon atoms connected by 

 an ethylene linkage are no longer free to rotate round the axis 

 which joins them " ; but so soon as an attempt is made to unite 

 these separate statements into one hypothe-is, or to assign any 

 reason for the proposition just quoted, it is impossible (as it 

 appears to me) to escape from the dilemma ; of the two alter- 

 natives, I think most chemists, who have not become blinded 

 by long usage to the gross misuse which the word " valency " 

 has suficrcd, will prefer to regard the carbon atom os finite in 

 size with four poims in it, occupying the coiners of a tetra 

 hedron, di'tingnished in some way beyond the rest as regards the 

 action of chemical affinity. 



This idea must be made more definite before the average 

 student can derive much help from it in correlating the facts of 



I WUIiccnu!! *.-iv* " tlic .ilom of carbon may possibly rcftcmble very closely 

 regular tetralicJron inshape." 



