340 



NATURE 



\_August 8, 1889 



the " Briefer Courses " becomes a positive blemish in the 

 advanced work. Indeed, the volume before us seems to 

 be nothing but the smaller work on inorganic chemistry 

 "writ large," since in point of knowledge the student is 

 not carried very much further than he is in that book. 

 Take, for example, the statement respecting the mode 

 of preparing hydrogen, given on pp. 26 and 27. We 

 read that, when sulphuric acid acts upon zinc, the che- 

 mical change is represented both qualitatively and quan- 

 titatively by the equation Zn -(- H2SO4 = ZnSOi + 2H. 

 This is stated without a word of qualification, in a long 

 paragraph on the complex nature of the changes which 

 take place in a chemical reaction ; and yet every teacher 

 knows that this equation does not express the truth, the 

 whole truth, and nothing but the truth about the matter. 

 Again, too, on p. 30, in the account of the mode of pre- 

 paring oxygen, we have the conventional methods of 

 representing the decomposition of potassium chlorate 

 into equal parts of perchlorate and chloride, and the 

 subsequent decomposition of the perchlorate into chlor. 

 ide, whereas Teed, and, subsequently, Frankland and 

 Dingwall, showed some years ago that these equations 

 altogether fail to represent what actually occurs. 



McLeod's work on the part played by the admixed 

 manganese dioxide in facilitating the evolution of oxygen 

 from potassium chlorate is perhaps too recent to have 

 received notice in the very meagre account given of the 

 supposed modes of action of this substance ; but the 

 space occupied by the description of" gnomium," which is 

 still more recent, might, we think, have been more profit- 

 ably employed by some mention of Mercer's theory of 

 " catalysis." This poverty of statement is, at times, 

 almost exasperating. The account of Lavoisier's work, 

 on p. 5, would have seriously jeopardized the chances of 

 a London University matriculant if given in an examina- 

 tion paper. Nine out of ten average students would 

 gather from this account that Lavoisier made chemistry 

 what it is to-day by proving why it was that, " whenever 

 water is boiled for a time in a glass vessel, a deposit of 

 earthy matter is formed." With respect to the etymology 

 of the term oxygen, it is stated that " the name is at 

 present somewhat misleading," which might imply that 

 it may possibly become less so in the future. On p. 298 we 

 are told that " it was in an examination of urine for the 

 purpose of discovering the philosopher's stone that 

 phosphorus was first discovered in 1669." On p. 383 

 it is stated that "the name soda-water had its origin in 

 the fact that the carbon dioxide used in charging the 

 water is frequently made from primary or acid sodium 

 carbonate." Are we to infer also that lithia and potash 

 waters are prepared from carbonic acid evolved from 

 the carbonate of the respective metals ? On p. 141 we 

 read that Lavoisier "considered chlorine to be an 

 oxygen compound of some undiscovered element which 

 was called murium. . . . The acid was accordingly called 

 muriatic acid. ..." If this implies that the term "muriatic 

 acid" was derived from murium^ it is contrary to La- 

 voisier's own account of the origin of the name. On 

 pp. 60 and 61 of his " Traitd Eldmentaire de Chimie," 

 partie i, chap. iii. (" CEuvres de Lavoisier," Imprimerie 

 Imperiale), " De la Nomenclature des Acides en general, 

 et particulierement de ceux tires du salpetre et du sel 

 marin," he says : — 



" Rien ne nous a ete plus facile que de corriger et de 

 modifier I'ancien langage a I'egard de ces acides ; nous 

 avons converti le nom d'acide vitriolique en celui d'acide 

 sulphurique, et celui d'air fixe en celui d'acide carbonique ; 

 mais il ne nous a pas ete possible de suivre le meme plan 

 a regard des acides dont la base nous ctait inconnue. 

 Nous nous sommes trouvds alors forces de prendre une 

 marche inverse, et, au lieu de conclure le nom de i'acide 

 de celui de la base, nous avons nommd, au contraire, la 

 base d'apres la denomination de I'acide. C'est ce qui 

 nous est arrive pour I'acide qu'on retire du sel marin ou 

 sel de cuisine. . . . Nous avons nomme cette base incon- 

 nue base inicriatiqiie, radical miiriatique, en empruntant 

 ce nom, k I'exemple de M. Bergman et de M. de Mor- 

 veau, du mot latin 7miria, donne anciennemenf au sel 

 marin." 



And in the index it is given : " Acide miiriatiqiie — son 

 nom derive du mot latin muria, 61." As a matter of fact, 

 the term was employed by Bergman and Scheele some 

 years before the Lavoisieran nomenclature was published. 

 Loose, imperfect, or partial statements are, in fact, to 

 be found on every other page. The word eudiometer is 

 derived from evSia, calm air, and fitrpov, a measure, " be- 

 cause it is used for the purpose of measuring gases (p. 51)." 

 On p. 61, dissociation is defined to be "the gradual 

 decomposition of a chemical compound by heat." Con- 

 trary to the statement on p. 44, hydrogen has not been 

 liquefied. If this gas does not unite with oxygen at ordinary 

 temperatures (p. 45), how is the action of platinum foil 

 and of the Dobereiner lamp explained ? The well-known 

 process of extracting silver from argentiferous lead is 

 called Pattison^s method (p. 598). On p. 304 it is stated 

 that phosphine unites with hydrochloric acid to form 

 phosphonium chloride, and the statement is made that 

 the reaction is perfectly analogous to that which takes 

 place between hydrochloric acid and ammonia. It is 

 nothing of the kind : phosphine and hydrochloric acid 

 only combine under pressure, and the compound is dis- 

 sociated, at ordinary temperatures, when the pressure is 

 released. To judge from the statement on p. 281, the 

 author is ignorant of the work of Tilden on the oxy- 

 chlorides of nitrogen. The rusting of iron (p. 693) is not 

 due to moisture in the air : iron does not rust in moist 

 air in the absence of carbonic acid, as every tin-plate 

 worker knows, and as Crace-Calvert, years ago, con- 

 clusively demonstrated. On p. 121 we have an account 

 of chlorine trioxide, although Garzarolli-Thurnlackh, 

 more than eight years since, working under Pebal's direc- 

 tion, showed that the substance so designated is a mix- 

 ture of the dioxide with varying quantities of free chlorine 

 and oxygen. The author still believes, apparently, in the 

 existence of the ammonium-amalgam, and wholly ignores , 

 the work which shows that it is nothing but a metallicj 

 froth. He incorrectly describes the action of sulphuric! 

 acid upon potassium permanganate (p. 683), and tells usj 

 that no oxygen compound of fluorine is known, in spitej 

 of the existence of an oxyfluoride of phosphorus. Thai 

 argument as to the valency of fluorine and the constitu-! 

 tion of fluosilicic acid (p. 416), based on the supposition f 

 that hydrofluoric acid has the molecular formula HjFg, 

 falls to the ground in view of the recent work of Thorpe 

 and Hambly. These by no means exhaust all the errors 

 we had noted, but the list is sufficiently long to show 

 that the book has apparently been hastily and somewhat 

 carelessly put together. It has, however, certain good 



