340 



NA TUKE 



[February 13, 1908 



their knowledge of him at second hand, so that his 

 discoveries and views are generally stated with more 

 or less inaccuracy. This becomes clear on perusing 

 the present work, a translation from the Latin ol 

 Mayow's five treatises, for which we are indebted 

 to the Alembic Club. 



The basis of Mayow's work was his recognition ol 

 the existence in the air and in common nitre of 

 extremely subtle particles to which he gave the name 

 " nitro-aerial spirit." He did not, however, as is 

 often supposed, regard air as a mixture of two gases, 

 as we do to-day, but considered the nitro-aerial par- 

 ticles to be " fixed in the aerial particles themselves," 

 and to be " torn from them by the burning of a lamp 

 or the breathing of animals." They are, in fact, 

 " neither air itself nor .some material interspersed 

 among its particles." Whilst the generally received 

 opinion is correct that Mayow recognised that an in- 

 crease of weight occurs when metals are burnt in air, 

 it is also true that he made but little use of this 

 fundamentally important observation ; in the main his 

 experiments were purely qualitative, and ingenious as 

 they often were, they served in many cases to dis- 

 tract the attention from the real issue. Had it been 

 otherwise the course of chemical history might have 

 been different. 



When it is remembered that, in Mayow's time, fire 

 and air, mercury, sulphur, and salt were regarded as 

 the fundamental elements, the clearness and origin- 

 ality of his views is very striking. He substitutes his 

 nitro-aerial spirit (which we now call oxygen) for air 

 and fire, and considers that out of the conflict of this 

 spirit with " sulphur " (that is, the combustible 

 constituent of substances) " all the changes of things 

 arise." At each step he feels his way by new experi- 

 ments, as, for example, when he shows that a mouse, 

 in breathing, diminishes the volume of air like a 

 burning candle, or that, when put in a glass vessel 

 along with a lamp, it will not breathe much longer 

 than half the time it would otherwise have lived. His 

 views on respiration are quite correct; by way of the 

 lungs " the aerial particles enter the mass of the 

 blood and are there deprived of their nitro-aerial par- 

 ticles." The latter are indeed " the principal instru- 

 ments of life and motion." He scoffs at the idea of 

 a vital flame as a source of animal heat, accounting 

 for the latter by " the nitro-aerial particles in the 

 blood fermenting with fts saline-sulphureous par- 

 ticles " (or, as we should say, by the oxidation of 

 combustible material). 



It was probably unfortunate that Mayow sought to 

 explain by the aid of his nitro-aerial spirit the most 

 diverse phenomena, such as the elasticity of solids, 

 the nature of light and colours, of lightning and the 

 transmission of nerve impulses, for in so doing the 

 more important facts established were obscured in a 

 haze of speculation which Mayow's early death pre- 

 vented him from dispelling; thus it happened that 

 exactly a century had to elapse before the work of 

 Scheele, Priestley, and Lavoisier led to a re-discoverv 

 of principles already clearly enunciated as early as 

 1674. 



W. A. D. 

 NO. 1998, VOL. 77] 



TOVJN GAS. 

 Town Gas and its Uses for the Production of Li^ht, 



Heat and Motive Power. By W. H. Y. Webber. 



Pp. vii + 275. (London : A. Constable and Co., Ltd., 



1907.) Price bs. net. 

 'T'HE opening lines to the preface of this book supply 

 the keynote to all that follows — " This book 

 is a summary of what I know, that appears to me 

 to be likely to interest a generally well-informed but 

 not technically instructed reader about the manufac- 

 ture of town gas and its uses." 



The author, who was for many years the subeditor 

 of the chief organ of the gas industry, has brought 

 to bear his wide knowledge and ripe experience of the 

 subject, and has given us a book that will be wel- 

 comed by all consumers of gas who desire an insight 

 into the mysteries of its manufacture, and the be^c 

 way to consume it for either heat, light, or power. 

 The term " town gas " is used in preference to coal 

 gas in order to cover the admixture of carburetted 

 water gas and coal gas now so often distributed as a 

 town supply, and which was necessitated chiefly by 

 the demand for high candle-power gas, whilst now 

 that the incandescent mantle has rendered rich gas 

 not only unnecessary but wasteful, it is to be sincerely- 

 hoped in the interests of the consumer that carbur- 

 etted water gas will disappear, and that only unadul- 

 terated coal gas will again become the general supply. 



Excellent as is the book as a whole, there are many 

 points that invite criticism ; it was to be expected that 

 the author would be an ardent champion of the virtues 

 of coal gas, but surely when (pp. 175, 176) he is com- 

 paring the relative cost of coal and gas as a fuel for 

 domestic use, and debits the cost of coal with a ser- 

 vant's wages and keep at 4?. a month, so bringing 

 the cost of the coal as a fuel to 5/. 15X. a ton, he is 

 going too far, and is more likely to do his cause 

 harm than good. Burnt in properly constructed gas 

 stoves, so arranged that none of the products of 

 combustion find their way into the air of the room, 

 coal gas is an ideal fuel, and, taking into consider- 

 ation the cleanliness, saving in labour, convenience, 

 and the fact that it need only be used when wanted, it 

 can be shown to be equal in cost at 2s. 6d. per 1000 

 cubic feet to coal at 245. per ton, but beyond this its 

 most ardent advocate would scarcely venture to go. 



Again, in speaking of the smoke curse and its pre- 

 vention, he says (p. 227), " Gas is the sole practicable 

 cure for this crying evil " — a statement which would 

 not be endorsed by the advocates of smokeless fuels, 

 such an anthracite, coke, coalite, or its imitations. 



Some small inaccuracies might with advantage be 

 corrected in a future edition; for instance, no gas 

 manager would be inclined to accept as an average 

 example of the normal supply to " the British Metro- 

 politan region " a gas containing i5'52 per cent, of 

 carbon monoxide, 15 per cent, of carbon dioxide, and 

 5"3i per cent, of nitrogen (p. 5). 



On p. 69 the author speaks of blue water gas being 

 made by the "methane-hydrogen plant "; this form 

 of apparatus, however, should be deleted from amongst 

 the " blue " gas plants, as its value is dependent upon 



