Oct. 28, 1880] 



NA TURE 



60 = 



a permanent difference would remain in the lengths of the two 

 spirals, that is, there would now be a permanent twist. 



Information regarding the fluidity of tempered steel, copper, 

 brass, lead, tin, &c., will be found in the papers of M. Treses, 

 and in the second of the Cantor lectures delivered by Mr. 

 Anderson before the Society of Arts April 19, 1S69, as well as 

 in Mr. Anderson's book on the " Strength of Materials," and in 

 Mr. Bottomley's reports communicated at the Meetings of the 

 British Association in 1S79-S0. We do not think, however, 

 that much of the valuable information on the fluidity of metals 

 which is scattered through the Proceedings of the different 

 societies has yet been collated. Wire-drawers, watch and 

 clockmakers, as well as the makers of philosophical instru- 

 ments and of other small machinery, have a considerable 

 amount of knowledge of this subject which they cannot 

 systematise and make known to others, but which; nevertheless, 

 they make ready use of in their work. 



Finally, we would suggest that if Major Herschel wants his 

 wire to obey Hooke's law for small twists only, he will not find 

 it necessary to destroy the properties which are due to its beijig 

 annealed. If, however, he desires to use greater twists, it will 

 be necessary to leave the wire under a fairly large pull for a 

 consideiable time without twisting it until it ceases to con- 

 tinuously yield to tensile stresses of greater intensity than that of 

 the shear stress to which it has afterwards to be subjected. 

 And if in Mr. Allan Broun's gravimeter it be necessary to 

 employ such large twisting couples as Major Herschel was using 

 in his experiments, we would suggest the employment of a longer 

 and thicker wire. John Perry 



London, October iS W. E. Ayrton 



On the Skin-furrows of the Hand 



In looking over some specimens of "prehistoric" pottery 

 found in Japan I was led, about a year ago, to give some atten- 

 tion to the character of certain finger-marks which had been 

 made on them while the clay was still soft. Unfortunately all 

 of those which happened to come into my possession were too 

 vague and ill-defined to be of much use, but a comparison of 

 such finger-tip impressions made in recent pottery led me to 

 observe the characters of the skin-furrows in human fingers 

 generally. From these I passed to the study of the finger-tips 

 of monkeys, and found at once that they presented very close 

 analogies to those of human beings. I have here few oppor- 

 tunities of prosecuting the latter study to much advantage, but 

 hope to present such results as I may attain in another letter. 

 Meanwhile I would venture to suggest to others more favourably 

 situated the careful study of the lemurs, &c., in this connection, 

 as an additional means of throwing light on their interesting 

 genetic relations. 



A large number of natm-e-prints have been taken by me ft-om 

 the fingers of people in Japan, and I am at present collecting 

 others from different nationalities, which I hope may aid students 

 of ethnology in classification. Some few interesting points may 

 here be mentioned by way of introduction. 



Some individuals show quite a yw/OTrfnVa/ development of these 

 furrows. In these cases all the fingers of one hand have a 

 similar arrangement of lines, while the pattern is simply reversed 

 on the other hand. A Gibraltar monkey (Macacus iunns) 

 examined by me had this arrangement. A slight majority of the 

 few Europeans I have been able to examine here have it also. 



An ordinary botanical lens is of great service in bringing out 

 these minor peculiarities. Where the loops occur the iunermost 

 lines may simply break off and end abruptly ; they may end in 

 self-returning loops, or, again, they may go on without breaks 

 after turning round upon themselves. Some lines also join or 

 branch like junctions in a railway map. All these varieties, 

 however, may be compatible v.itli the general impression of 

 symmetry that the two hands give us when printed from. 



In a Japanese man the lines on both thumbs form similar spiral 

 whorls ; tho.e of the left fore-finger form a peculiar oval whorl, 

 while those of the right corresponding finger form an open loop 

 having a direction quite opposite to that of the right fore-finger 

 in the. previous example. A similar whorl is found on both 

 middle fingers instead of a symmetrically reversed whorl. The 

 right ring-finger again has an oval whorl, but the corresponding 

 left finger shows an open loop. 



The lines at the ulno-palmar margin of tliis particular Japanese 

 are of the parallel sort in both hands, and are quite symmetrical, 

 thus differing from the Englishman's considerably. These in- 



stances are not intended to stand for typical patterns of the two 

 peoples, but simply as illustrations of the kind of facts to be 

 observed. My method of observation was at first simply to 

 examine fingers closely, to sketch the general trend of the curves 

 as accurately as possible, recording nationality, sex, colour 06 

 eyes and hair, and securing a specimen of the latter. I passed " 

 from this to "nature-printing," as ferns are often copied. 



A common slate or smooth board of any kind, or a sheet of 

 tin, spread over very thinly and evenly with printer's ink, is all 

 that is required. The parts of -which impressions are desired 

 are pressed down steadily and softly, and then are transferred to 

 slightly damp paper. I have succeeded in making very delicate 

 impressions on glass. They are somewhat faint indeed, but 

 would be useful for demonstrations, as details are very well 

 shown, even down to the minute pores. By using different 

 colours of ink useful comparisons could be made of two patterns 

 by superposition. These might be shown by magic lantern. I 

 have had prepared a number of outline hands with blank forms 

 for entering such particulars of each case as may be wanted, and 

 attach a specimen of hair for microscopic examination. Each 

 finger-tip may best be done singly, and people are uncommonly 

 willing to submit to the process. A little /lot \\ ater and soap 

 remove th'> ink. Benzine is still more effective. The donii- 

 nancy of heredity through these infinite varieties is sometimes 

 very striking. I have found unique patterns in a parent repeated 

 with marvellous accuracy in his child. Negative results, how- 

 ever, might prove nothing in regard to parentage, a caution 

 which it is important to make. 



I am sanguine that the careful study of these patterns may be 

 useful in several ways. 



1. We may perhaps be able to extend to other animals the 

 analogies found by me to exist in the monkeys. 



2. These analogies may admit of further analysis, and may 

 assist, when better understood, in ethnological classifications. 



3. If so, those which are found in ancient pottery may become 

 of immense historical importance. 



4. The fingers of mummies, by special preparation, may yield 

 results for comparison. I am very doubtful, however, of this. 



5. When bloody finger-mai-ks or impressions on clay, glass, 

 &c., exist, they may lead to the scientific identification of 

 criminals. Already I have had experience in two such cases, 

 and found useful evidence from these marks. In one case 

 greasy finger-marks revealed who had been drinking some 

 rectified spirit. The pattern was unique, and fortunately 

 I had previously obtained a copy of it. They agreed with 

 microscopic fidelity. In another case sooty finger-marks of 

 a person climbing a \ihite wall were of great use as negative 

 evidence. Other cases might occur in medico-legal investi- 

 gations, as when the hands only of some mutilated victim 

 were found. If previously known they would be much more 

 precise in value than the standard mole of the penny novelists. 

 If unknown previously, heredity might enable an expert to deter- 

 mine the relatives with considerable probability in many cases, 

 and with absolute precision in some. Such a case as that of the 

 Claimant even might not be beyond the range of this principle. 

 There might be a recognisable Tichborne type, and there might 

 be an Orton type, to one or other of which experts might relate 

 the case. Absolute identity would prove descent in some 

 circumstances. 



I have heard, since coming to these general conclusions by 

 original and patient experiment, that the Chinese criminals from 

 early times have been made to give the impressions of their 

 fingers, just as we make ours yield their photographs. I .have 

 not yet, however, succeeded in getting any precise or authenti- 

 cated facts on that point. That the Egyptians caused their 

 criminals to seal their confessions with their thumb-nails, just as 

 the Japanee do now, a recent discovery proves. This is ho\y- 

 ever quite a different matter, and it is curious to observe that in 

 om' country servant-girls used to stamp their sealed letters in the 

 same way. There can be no doubt as to the advantage of having, 

 besides their photographs, a nature- copy of the for-ever-unchange- 

 able finger-furrows of important criminals. It need not surprise 

 us to find that the Chinese have been before us in this as in other 

 matters. I shall be glad to find that it is really so, as it would 

 only serve to confirm the utility of the method, and the facts 

 which may thus have been accumulated would be a rich anthro- 

 pological mine for patient observers. Henry Faulds 



Tsukiji Hospital, Tokio, Japan 



[Some very interesting examples of nature-printed finger- 

 tips accompanied this letter. — Ed.] 



