NATURE 



[July 21, 19 10 



connection will appreciate the advantage of making 

 the distinction. It is, however, to be regretted that 

 in the matter of notation the author is too intensely 

 German. He puts P for force, A for energy, L for 

 power, D for torque, and so on, all letters which have 

 internationally already a significance. The reader is 

 thus put unnecessarily to the trouble and mental strain 

 to substitute for symbols he is accustomed to use (and 

 which, to a certain degree, have already received the 

 sanction of the International Electrotechnical Commis- 

 pion) others which are unfamiliar to him. 



It is not necessary to enumerate the contents of this 

 book in detail ; suffice it to say that it broadly covers 

 the subject of la-boratory tests such as are necessary 

 for students. As to the question of which tests are 

 necessary and which may be omitted, opinions will 

 always differ. Tt would be easy to give a list of 

 tests which, in the reviewer's opinion, ought to have 

 been included, but such criticism would hardly be 

 fair, for a book on testing cannot contain every pos- 

 sible test, but only a selection of those which the 

 author himself has found suitable. On the whole, the 

 author has given us a very representative and useful 

 selection, covering a wide field. His book will be 

 found to be a most helpful guide to electrical laboratorv 

 work generally. Gisbert Kapp. 



ANCIENT HINDU CHEMISTRY. 

 A History of Hindu Chemistry from the Earliest 

 Times to the Middle of the Sixteenth Century A.D., 

 uiitli Sanskrit Texts, <5>-e. By Prof. Praphulla 

 Chandra Ray. Vol. ii. Pp. xcvi + 293 + 152 + xxi. 

 (Calcutta : The Bengal Chemical and Pharmaceu- 

 tical Works, Ltd. ; London : Williams and Norgate, 

 1909.) Price los. 6d. net. 



IN the first volume of this book, which was pub- 

 lished in 1902, and reviewed in these columns on 

 May 21, 1903, Prof. Ray dealt with all the oldest (pre- 

 Buddha) Hindu MSS., and many of the later ones. 

 A number of MSS. remained untouched, and now 

 that these have been examined, the concluding volume 

 has been issued. It has been a labour of love which 

 has occupied all Prof. Ray's spare time for the last 

 fifteen years, and the great value of the results of 

 his patient and laborious researches will be fully appre- 

 ciated by all students of the history of chemistrv. 



The difficulties of determining the extent of Indian 

 chemical lore in ancient times are profound. There is 

 no doubt that at a very early period the .'\rians 

 attained great proficiency in the manufacturing indus- 

 tries, which must have rested on a good practical 

 knowledge of chemical reactions. The famous sword- 

 blades, called by the Greeks "marvellous swords," 

 and by the Western world "Damascened blades," were 

 brought to Europe by way of Damascus, but were 

 made in India. The making and polishing of glass in 

 India, including lenses and mirrors of various kinds, 

 spherical, oval, &c., was a well-known industry. Plinv 

 mentions that the best glass ever made was Indian 

 glass. In pharmacy, in dyeing, in the manufacture 

 of perfumery and cosmetics, complicated chemical 

 operations must have been carried out even before th€ 

 time of Buddha, which is placed ^bout B.C. 500. 



There is, however, little or no trace of these things 

 NO. 2125, VOL. 84] 



in the literature of the period. The caste system was 

 radicallv opposed to the formation of a science in 

 which practice is based on theory. The chemical in- 

 dustries were exercised by a despised caste, that of 

 the fitdras, and their labours were no doubt deemed 

 unworthy of being described by the caste of the 

 Brahmins, or priests, who alone understood the art 

 of writing. Thus Hoefer, for example, remarks that 

 amongst the Sanskrit manuscripts in the Bibliothfeque 

 Imperiale, of Paris, no document occurs which can 

 be of interest to the historian of chemistry, and 

 Berthelot in his " Origines de I'Alchemie " practically 

 ignores India. 



The MSS. patiently examined by Prof. Ray appear 

 to consist largely of religious or philosophical reflec- 

 tions, with occasional somewhat obscure references to 

 chemical subjects made for the purpose of illustration. 

 Thus in a document called " Rasaratnakara," written 

 by Nagarjuna, who was the High Priest of Buddha 

 about A.D. 150, such texts as the following occur : — 



"What wonder is it that cinnabar digested several 

 times with the milk of the ewe and the [vegetable] 

 acids imparts to silver the lustre of gold glowing as 

 saffron? " 

 And a little further on : — 



"Silver alloyed with lead and fused with ashes 

 becomes purified," 

 which is a clear allusion to cupellation. 



It is probable that the pundits, when referring to 

 metal-working, often knew very little of the subjects 

 thev mentioned, but Nagarjuna was celebrated as an 

 alchemist. Prof. Ray argues at some length in 

 favour of the indigenous origin of Indian alchemy, 

 and, however degrading it may have been to work, it 

 does not appear to have been derogatory to the dignity 

 of the sages to discuss the manufacture of gold or 

 silver. Thus — 



"Tin is to be melted and one-hundredth part its 

 weight of mercury to be amalgamated with it. This 

 [fraudulent substitute for] silver can be used for pur- 

 poses of exchange, and one can thus amass wealth." 



The last 150 pages of the book consist of a repro- 

 duction of original Sanskrit texts, taken from many 

 different MSS. T. K. R. 



AN ENCYCLOPAEDIA OF THE SCIENCES. 

 Instruments optiques d'Observation et de Mesiire. 

 By Jules Raibaud. Pp. 380. (Paris : O. Doin et 

 Fils, 1909.) Price 5 francs. 



THIS volume is a unit in a somewhat extensive 

 undertaking, no less than an encyclopaedia of 

 all the sciences, pure and applied, physical and 

 biological, material, mental, and moral. The scheme 

 is of a somewhat novel character; its magnitude may 

 be judged from the fact that it involves a total of some 

 thousand volumes, arranged in forty sections or 

 "bibliothfeques," the whole to rival, we are told, the 

 largest entyclopsedias of this or any other country — 

 and not only in size. The novelty lies mainly in the 

 fact that each volume is to be independent, and have 

 its own individuality ; each will be a monograph 

 dealing with a special branch of the particular section 

 to which it belongs. The size and price will be 

 uniform, the number of pages approximately so. One 



