270 



NA rURE 



[January 19, 1905 



least one thing is certain — the writing-fluid used by 

 the ancient scribes for such records as the foregoing 

 must have possessed in a high degree the property of 

 durability. 



In one form or another, the basis of these early 

 writing-fluids was carbon. For example, Chinese ink, 

 the so-called " Indian " ink of the modern artist, which 

 according to the native historians has been made since 

 2600 B.C. or thereabouts, was at first a vegetable 

 varnish, and later a mixture of lampblack and glue. 

 Inks containing gallate of iron did not come into use 

 until a much later period. Tlius Sir Humphry Davy, 

 examining some documents recovered from the ruins 

 of Herculaneum, " looked in vain amongst the MSS. 

 . . . for vestiges of letters in oxide of iron," and he 

 concludes that the Romans up to the time of Pliny 

 had never used " ink of galls and iron " for writing 

 purposes. Gradually, however, in the early centuries 

 of the Christian era, there came a transition from 

 carbon inks to those containing iron; and Blagdcn, in 

 " Some Observations on Ancient Inks," communicated 

 to the Royal .Society in i7<S7, records that the writing 

 fluid employed in various MSS. on vellum, dating from 

 the ninth to the fifteenth centuries, was an iron and 

 gall ink. .Somewhat earlier than the date of Blagden's 

 paper logwood began to find employment as a con- 

 stituent of inks, and soon after the middle of last 

 century came the next notable modification, namely, 

 the use of aniline dyes in the manufacture of both 

 black and coloured writing-fluids. 



Of these and other matters bearing upon the history, 

 composition, and methods of preparing the various 

 kinds of inks, Messrs. Mitchell and Hepworth have 

 much to tell us in the volume under notice. They 

 have brought together, and made convenient for 

 reference, material that has been hitherto chiefly 

 scattered amongst periodicals and isolated dictionary 

 articles. In so doing they have saved their con- 

 temporaries some labour, and earned for themselves 

 much gratitude. 



The book is divided inlo ihree si-clioiis. The first 

 of these deals with writing inks, including those of 

 which carbon, tannin, logwood, and aniline re- 

 spectively form the characteristic ingredients. It 

 comprises chapters upon the sources of the tannin 

 materials, the chemical nature of iron-gall inks, and 

 the best methods of examining both the fluid itself and 

 the characters on the written page. Printing inks 

 form the subject of section ii., in which an interesting 

 chapter treats of colour work, including three-colour 

 printing and inks for use in the production of cheques 

 ;ind bank-notes. In the concluding section there is a 

 description of inks intended for miscellaneous pur- 

 poses; these comprise copying, marking, safety, and 

 sympathetic inks, and fluids for writing on glass, 

 wood, ivory, or leather. Many formulae are given, 

 some of which the authors have personally tested, and 

 Ihe work closes with a list of English patents relating 

 10 the subject. 



Despite occasional incoherency of style, the two 



collaborators have produced a useful and attractive 



little volume. One or two slips may be pointed out; 



thus the equation on p. loi is incomplete, and the 



NO. 1838, VOL. 71] 



specific gravity of dilute hydrochloric acid is given 

 wrongly on p. 20S. In the historical introduction we 

 are told, apropos of a certain document (p. 11), that 

 " it was probably written at the end of the sixteenth 

 century by a man past middle age, who learned to 

 write just about the time that Shakespeare was born 

 (1504)." At first it seems an unnecessarily cautious 

 understatement to call such a man " past middle age," 

 but a little reflection shows that it is those kittle cattle 

 the figures that are to blame. 



The book is a serviceable addition to the literature 

 of chemical technology. C. Simmo.nds. 



OUR BOOK SHELF. 

 Nalurhc griff c iind Xaturniicilc. By Hans Driesch. 



Pp. viii + 239. (Leipzig: Wilhelm Engelmann ; 



London : Williams and Norgate, 1904.) Price 44. 



net. 

 This book deals chiefly with three topics. Starting 

 on a Kantian basis, it seeks to state the a priori prin- 

 ciples of pure physical science. (.1 priori is con- 

 veniently defined as " independent of the amount of 

 experience.") Next, the leading principles of 

 " energetics " are discussed, and their relation on the 

 one hand to the o priori principles of pure physical 

 science, and on the other hand to the ordinary laws 

 of thermodynamics. Incidentally, the " laws " of 

 conservation (of substance and the like) are examined, 

 and entropy has a good deal of attention. Last of all 

 the results attained are carried over to a discussion of 

 biology. The point of view is neo-vitalistic. It would 

 be hazardous to say that the author has run to earth 

 the X which is the object of all our search, the vital 

 principle or whatever other name may be applied to 

 it ; the term which he uses is the blessed word 

 enteh'chy. 



Herr Driesch is well known to be at his best a 

 clear, original and suggestive writer. Much of the 

 present work is excellent, but we doubt if the last 

 eightv pages are either clear or convincing. Perhaps 

 one would require to read the author's other works 

 in order to accustom oneself to his point of 

 view and his independent modes of statement. He 

 is occasionally unsatisfactory as well when dealing 

 with the theories of others, for example, with Prof. 

 Clerk Maxwell's " sorting demon." The discussion 

 occurs under the heading " Declarations of Physicists 

 regarding Biological .Subjects," and Herr Driesch 

 almost seems at times to suppose or to imply that the 

 conception may have been formed in order to limit 

 the second law of thermodynamics to inanimate bodies. 

 True, Lord Kelvin's statement of the second law has 

 the words " in inanimate material." But Lord 

 Kelvin's declaration is explicit (" Popular Lectures and 

 Addresses," 1889, vol. i. p. 141) : — " The conception 

 of the ' sorting demon ' is merely mechanical and is 

 of great value in purely physical science. It was not 

 invented to help us to deal with questions regarding 

 the influence of life and of mind on the motions of 

 matter." On p. 103 the accurate reference to Helm- 

 holtz's work is — Ostwald's Klassikcr Nr. 124, p. 30, 

 Anm. 



Higlier Text-book of Magnetism and Electricity. By 



R. Wallace Stewart, D..Sc. Being vol. iv. of " The 



Tutorial Physics." Pp. viii + 672. (London : W. B. 



Clive, University Tutorial Press.) Price 6.s. 6d. 



Wk have several times noticed this work as successive 



editions have appeared, and can speak as appreciatively 



of it as we have on other occasions. The present 



volume is based on the older one, but it has been wholly 



