December 23, 1922J 



NA TURE 



845 



The Track of a Flat Solid falling through Water. 



By using a small crystal of silver nitrate as the 

 " flat solid " and acidulating the water with HC1 the 

 track becomes visible, as seen in the repro- 

 duction (Fig. 1). 



It was by no means easy to "catch" 

 the effect, and I have to thank two 

 members of the Chemical Society of this 

 College, G. R. Ellis and C. P: Sayles, 

 for all the patience and care taken in 

 obtaining so successful a result. 



E. W. Wetherell. 

 Liverpool College, Liverpool. 



Water Snails and Liver Flukes. 



Dr. Monica Taylor states in Nature 

 ofNovember25, p. 701, that further inquiry 

 is desirable in respect to the intermediate 

 hosts of the fluke, as in some districts 

 where water snails are rare or altogether 

 absent, yet in these districts sheep are 

 subject to liver-rot disease. May I add 

 another point ? In the Swansea valley, 

 county of Glamorgan, farmers state very 

 definitely, as the result of years of experi- 

 ence, that liming the land increases the 

 liver fluke, for sheep can be run on the 

 rough pastures in the area with slight 

 loss from liver-rot disease, before it is 

 limed : but after it has been so treated 

 the loss from liver-rot disease becomes 

 heavy, sometimes serious. Theories re- 

 garding this are many and varied, but the 

 fact remains that the loss from liver-rot 

 in any given area of land is definitely 

 increased after liming. Does liming a wet 

 sour pasture make it more congenial to 

 the water snail ? R. Hedger Wallace. 



November 28, 1922. 



The Cause of Anticyclones. 



The steady and persistently high barometric pres- 

 sure that has prevailed over southern England during 

 most of the autumn naturally causes the desire to 

 know how an anticyclone is produced and maintained 

 in such a situation, but the explanations current in 

 meteorological literature are not for the most part 

 efficacious. It is commonly stated that the high 

 pressure is due to a mass of cold and therefore 

 heavy air above it, but for Europe at least this is in 

 direct opposition to observational results, which show 

 that some three-quarters of the whole mass of air 

 over an anticyclonic area is unduly warm. It is the 

 mass of air over the area that is important ; its tem- 

 perature is quite immaterial, and the real difficulty is 

 to explain why the excess of air does not roll off. 



A lecturer demonstrating the gaseous laws must 

 provide himself with a closed vessel in which to 

 confine his gas, and if by any means he spills a 

 pound of mercury on his table he will not expect to 

 find it there in a convenient heap the next day or 

 the next week. The meteorologist, on the other hand, 

 having provided his " polar " air does not proceed to 

 Explain why it remains in situ and does not rather 

 follow the ordinary law of a fluid finding its own level. 

 The difficulty should be faced and not ignored. 

 Doubtless the equivalent of the lecturer's closed vessel 

 is the geostrophic wind surrounding the anticyclone, 

 but one would like to know how the wind is produced 

 and why and how it is maintained. 



W. H. Dines. 



Benson, WaUinsrford, December 1. 



Stelzner, unbound, 

 /ol. 1. Vol. 2. Vol. 3. 



24 38 100 



German Book Prices. 



There has been much comment recently in England 

 and America on the above subject : see particularly 

 an article by Prof. Noyes (/. Ind. Eng. Chem., 1922, 

 99), and editorial comments in the same journal, 1922, 

 475- 



The following prices are examples : 



Beilstein, bound. 

 Vol. I. Vol. 2. Vol. 3. Vol. 4. 

 England, shillings . 40 38 102 no 



Germany, marks . no no 280 330 



The prices charged to members of the German 

 Chemical Society seem so peculiar that I recently 

 wrote to the society pointing out that much dis- 

 satisfaction had been expressed at this state of affairs, 

 and received an answer, from which, as it is too long 

 to insert in full, the following curious passages have 

 been extracted : " . . . Reckoned on the number of 

 pages the prices are much smaller than those of the 

 publications of almost all foreign chemical societies. 

 The justice of our fixed prices was confirmed a few days 

 ago from Switzerland. [The italics are mine.] There 

 can be no thought of making foreign and German 

 prices equal so long as we Germans are compelled to 

 spend unnumbered thousands of our depreciated 

 marks to obtain English books . . ." 



It is amusing to note the proud reference to the 

 bulk of the journal, which enhances its value so much 

 in German eyes. The diffuseness of their publica- 

 tions is considered in most countries to be a dis- 

 advantage ; recent complaints were about the quality, 

 not quantity. As to the remark about Germans 

 having to spend many marks to purchase foreign 

 books, the obvious comment is that they need not 

 have printed such a lot of paper money. 



Was there not an article in the Treaty of Versailles 

 by which Germany undertook not to impose on 

 British subjects any other or any higher direct or 

 indirect fees, dues, or tax, than are imposed on 

 German citizens ? 



In the circumstances, I am sure most chemists 

 will agree that until treaties with Germany are some- 

 thing more than scraps of paper, money expended in 

 subscriptions to the German Chemical Society is not 

 much better spent than in buying paper marks. 



It is to be hoped that the English and American 

 Chemical Societies will soon be in a position to publish 

 a Dictionary of Organic Chemistry at a fixed reason- 

 able price and in a reasonably terse language. 



K. C. Browning. 



16 Bridge Avenue Mansions, 



Hammersmith, W.6, December 1. 



Medical Education. 



In Nature for December 9, p. 769, Sir Archdall Reid 

 asks the following question : " But can any one tell 

 us of what utility, practical or intellectual, is the 

 biology which medical students learn — facts about 

 the classification of plants, the vascular system of the 

 sea urchin, the digestive system of the leech, the 

 bones in the cod's head, and so on ? 



I am not quite clear whether this question has been 

 propounded to invite answers, or to introduce 

 another of Sir Archdall Reid's favourite discussions 

 on mutations and fluctuations, etc. There is, how- 

 ever, scarcely any need to answer the question. So 

 far as I am aware, the biology offered to medical 

 students to-dav is very different from that suggested 

 by Sir Archdall Reid in the lines from his letter 

 quoted above. W. J. Dakin. 



Zoology Department, University of Liverpool, 

 December n. 



NO. 



2773, VOL. I IO] 



