3o 



NA TURE 



[July 8, 1922 



importance. It was this point which went far towards 

 determining the general trend of the Report of the 

 Committee of the Conjoint Board. 



The present policy of the Decimal Association must 

 be examined with this difference in mind. The As- 

 sociation suggests a step-by-step transition, leading 

 to a gradual familiarisation of the country with metric 

 units, until the opposition is so far reduced that a 

 compulsory metric system Act becomes possible. As 

 a first step, the pound avoirdupois is to be readjusted 

 so as to become exactly equal to half a kilogram — 

 an increase of about 10 per cent. The official policy 

 of the Association is to alter the ounce, dram, and 

 grain similarly, retaining their present ratios. Dr. 

 Guillaume prefers, if there is to be a " piecemeal " 

 policy, to make the new pound (500 grams), contain 

 20 ounces, 250 drams, and 10,000 grains, the per- 

 centage changes in magnitude being of about the 

 same order, but not all in the same direction. 



It will be seen that, in itself, a change of this sort 

 could probably be made without serious difficulty, if 

 it were thought to be necessary. . That is to say, if 

 a deliberate and agreed decision had been come to 

 that the metric system exclusively was to be employed 

 in Great Britain, the transition might well have been 

 begun in this way. In the absence of such a decision, 

 the position is less clear. A certain amount of in- 

 convenience must inevitably arise, particularly in the 

 introduction of a new series of weights and measures 

 in retail trade ; and although the ultimate introduc- 

 tion of the metric system might be facilitated by the 

 proposed modification, it is scarcely likely that those 

 who are opposed to the end in view will offer any less 

 opposition to the means employed. Faced with the 

 ultimate proposal, that the inch should be altered to 

 constitute one-fortieth of a metre — and this is prob- 

 ably the least objectionable line of action open — no 

 concession is to be expected from opponents in 

 favour of a first step, which does not, in itself, present 

 very obvious advantages. It is probably far too 

 seldom realised that the great objection to the metric 

 system is based upon the incommensurability of the 

 British and metric units of length. The real battle 

 lies between the inch and the centimetre. If the 

 alteration of either, to make it commensurable with 

 the other, could be admitted, then its ultimate aboli- 

 tion could follow without much difficulty. 



The view is quite widely held that the Imperial 

 units are, as magnitudes, more suitable for commercial 

 purposes than the metric. There is, therefore, at least 

 a possibility that the solution of the metric contro- 

 versy may be found in the development of a system 

 based upon the British units, but so modified as to 

 be capable of treatment on pure decimal lines. The 

 NO. 2749, VOL. I 10] 



Report of the Committee of the Conjoint Board sug- 

 gests that the possibilities of such a solution should 

 be explored, and one experiment in this direction has 

 already been tried with success. The troy pound was 

 abolished in 1878, but the troy ounce was too firmly 

 established to be dismissed entirely. Trade in the 

 precious metals, however, is now carried on in terms 

 of troy ounces only, and bullion weights are made up 

 solely in decimal multiples and sub-multiples of that 

 unit. There has certainly been some activity in this 

 direction in recent years, and should a really logical 

 system upon a decimal basis be devised and secure 

 general acceptance in the countries now using Imperial 

 units, it may be found that these units are, after all, 

 destined to survive. R. J. T. 



Influenza. 



Influenza : Essays by several Authors. Edited by F. G. 

 Crookshank. Pp. xii + 529. (London : W. Heine- 

 mann (Medical Books), Ltd., 1922.) 30.?. net. 



A VALUABLE series of essays is given in this 

 volume, bringing our knowledge of this devas- 

 tating disease up-to-date, and at the same time demon- 

 strating the nebulous character of this knowledge and 

 our impotence in face of its recurring pandemics. From 

 the wider point of view the contributions of Drs. 

 Crookshank and W. H. Hamer are especially valuable. 

 The seven chapters contributed by Dr. Crookshank 

 would have been even more valuable than they now 

 are, had he condensed them and treated his subject 

 more systematically. They bear evidence of previous 

 separate publication, with considerable repetition and 

 occasional laxness in sequence of matter. 



The rest of the volume is occupied by chapters on 

 the clinical and therapeutic aspects of influenza, which 

 need not detain us, and by a chapter of 175 pages 

 dealing with the bacteriology of influenza, which would 

 have gained greatly by severe condensation. 



The chief interest of the volume, however, consists 

 in a full statement of the special views respecting 

 influenza which the lucid and skilful writing of Dr. 

 Hamer, ably seconded by Dr. Crookshank, has rendered 

 important ; and every one wishing to study the epi- 

 demiology of influenza, and to learn another view than 

 that apparently favoured in the official report of the 

 Ministry of Health, will need to study these chapters 

 carefully. 



The question at issue is whether influenza, in the 

 various forms which are usually recognised as this 

 disease, is a single specific disease, due to a special 

 contagium, which may or may not be the Pfeiffer 

 bacillus ; or whether the same virus may not also be 

 the cause of " phases " of influenza, including cases 



