HO 



NATURE 



[Fed. 29, 1872 



collected from the vessels of a dog without the loss of any 

 of the water by evaporation, whilst at the same time, being 

 frozen, it loses its disposition to coagulate, and when sub- 

 sequently thawed can be readily manipulated. The mean 

 of four analyses gave the following results : — 



Phosphoric acid anhydride .... O'lioj 

 Sulphuric acid anhydride .... 0'0358 



Chlorine o-2So5 



Potash 00342 



Soda 0-3748 



Lime 001 12 



Magnesia . 00058 



Oxide of iron 00948 



Total ash found 0S922 



Calculated 0S640 



In Verdeil's treatise, the amount of ashes of fresh blood 

 is stated to be on the average 6-45 per cent. Jarisch points 

 out that this must be an error ol the press, his own results 

 giving only 0864 per cent., a difference that is too great 

 to be regarded as an error of analysis. 2. An essay on 

 the Centres of Vascular Nerves, by Dr. Soboroff. In this 

 paper Ur. Soboroff shows from the results of experiments 

 performed on frogs that the nerves supplying the vessels 

 of the web of the foot proceed from the spinal cord, and 

 run into the sciatic nerve. 3. On the presence of Fungi in 

 theBloodof HealihyMen,byAdolph Lorstorfcr. Lorstorfer 

 drewblood from thefingers of eleven people who considered 

 themselves in perfect health with every precaution to 

 avoid contamination with dirt, and examined the specimens 

 daily with a Hartnack microscope, ocular 3, objective 10. 

 During the first two days he observed nothing remarkable, 

 except in some cases a few scattered groups of small 

 granules. On the third day similar groups were always 

 found, though still scattered. The granules were of equal 

 size, considerably larger than those of the colourless 

 blood corpuscles, but without any definite arrangement. 

 On the fourth day they had increased in size, and were 

 arranged in groups of four, so as to resemble the well- 

 known Sarcina vciitiiculi. On the fifth day the granules 

 had slightly increased in number and size, but after this 

 date no change was observable up to the tenth day, when 

 the preparations became unserviceable. Lorstorfer thinks 

 his experiments render it probable that the germs of 

 Sanina vcntrkiili exist in the blood as a natural condi- 

 tion. There are three other papers, but they are all of a 

 purely professional nature. One being by Hofmokl on 

 Resection of the Upper and Lower Jaw : one by Bress- 

 lauer on Typhus : and one by Popoff on Pneumonia. 



H. P. 



LETTERS TO THE EDITOR 



[ The Editor does not hold himself responsible for opinions expressed 

 by his correspondents. No notice is taken of anonymous 

 communications. ] 



Development of Barometric Depressions 



I HAVE only just had my attention called to the critique on 

 "The Laws of the Winds prevading in Western Europe," in 

 Nature of Jan. 11, which 1 liave seen to-day for the first time. 

 Though it is now ratlier late to do so, I may perhaps be per- 

 mitted to point out some unintentional misrepresentations of my 

 views into which the writer appears to me to have fallen. 



He considers it improbable in the extreme that the course of 

 baric depressions should be regulated "by one law" in intra- 

 tropical, and by "a totally distinct law" in extra-tropical regions 

 of the globe. I pointed out (pp. 40, 41) that in temperate 

 latitudes the general distribution of atmospheric pressure com- 

 monly tends to transfer local depressions in an eastward direc- 

 tion ; while the influence of precipitation resulting from the mean 

 distribution of solar heat propagates them in the same direction. 

 Since the reversal of pressure-distribution which accompanies 

 polar periods only retards the eastward progression, I drew the 



conclusion that, in temperate latitudes, the most important of the 

 two factors of the progression is the influence of precipitanon, 

 and accordingly I devoted the first part of my work to this, with 

 the promise (which I hope shordy to redeem) that the motive 

 effect of the general pressure-distribution shiU be described in 

 Part II. All this your reviewer ignores. Had I been engaged 

 in a discussion of the tropical cyclones, I should have proceeded 

 in an inverse order ; since the most important factor of their 

 westward progression appears to be the mechanical influence of 

 the distribution of surrounding pressures. It is, however, im- 

 portant to observe that as in temperate, so in tropical latitudes, 

 these two influences are commonly coincident in direction. In 

 the West Indies, c.g.—^X. those periods when cyclones prevaU— 

 mean temperatures are lower on the south, or left, than on the 

 north, or right, of their course; and a similar remark applies, 

 mutatis mutandis, to the typhoons of the Indian and China seas. 

 Briefly, my position is this. The influence of the general dis- 

 tribution of temperatures, and that of the general distribution of 

 pressures, may be practically regarded as two forces, A and B, 

 Irom which the progression of local depressions results. Both of 

 these commonly act in the same direction— in temperate latitudes 

 producing eastward, and in tropical westward, progression. But 

 of these A is the preponderating influence in temperate, B in 

 tropical latitudes ; partly because the influence of precipitation 

 on the surface-currents increases with diminution of temperature, 

 and paitly because the currents resulting from the general distri- 

 bution of pressures are far more constant and of vastly greater 

 extent, in proportion to the extent of the cyclones, in tropical 

 than in temperate latitudes. I am convinced that the attempt to 

 simplify the rules which regulate the progression of depressions by 

 striking out either of these factors, or by the substitution of 

 J. K. L.'s single law, wdl meet, as it has hitherto met, with 

 tailure. 



\'our reviewer also ignores what I have said (pp. 28, 29) as 

 to the occurrence of heavy precipitations unproductive of baric 

 depression, and thinks it necessary to travel to Khasia or to the 

 Himalayas to find illustrations of a truth which it was never in- 

 tended to deny. Every one conversant, as he considers me to 

 be, with the meteorology of Western Europe alone, is aware that 

 heavy and extensive precipitation not uncommonly occurs with- 

 out producing retrograde circulation (and sometimes with gene- 

 rally increasing pressures), where antecedent atmospheric con- 

 ditions do not lavour such developments. The reviewer concedes 

 that the immense precipitation in the Himalayas "probably 

 causes a very great barometric depression ; " a concession which 

 is not to be accepted, both because such a reference to antecedent 

 probabilities is inapplicable to empirical science, and because the 

 fact itself may be denied. But supposing this great Himalayan 

 depression to exist, and no retrograde circulation (as J. K. L. 

 maintains) to be developed around it, his discovery of a region 

 in which ' ' Ballot's rules " are contravened, is mdeed one of no 

 small importance. 



Into the wide question of the influence of the earth's rotation 

 I wUl not here enter, further than to remark that the hitherto 

 admitted universality of the rules connecting the direction of all 

 atmospheric currents with the distribution of surrounding 

 pressures, and the variation of these rules in the two hemispheres, 

 appears to have been satisfactorily accounted for by attributing 

 it to the earth's rotation; while it has never been, with much 

 plausibility, traced to any other cause or combination of causes. 

 Hereford, Feb. 17 



W. Clement Ley 



Zoological Nomenclature 



In the President's address to the Entomological Society of 

 London recently given by Mr. Wallace, one of the points most 

 fully discussed is the rules of zoological nomenclature. These 

 rules are undoubtedly of very considerable, though indirect, im- 

 portance to science, and it is not very satisfactory to find that 

 great divei'gence of opinion as to what these rules are, or should 

 be, still prevails amongst recent describers and cataloguers. 



Some years ago I was entrusted liy the Entomological Society 

 vrith the task ot preparing a synonymical catalogue of the Cole- 

 optera of our islands, to be published under the auspices ol the 

 Society ; my attention, therefore, has necessarily been directed 

 to the questions under discussion in this matter, and I will here 

 state the conclusions to which I have come. 



1st. That a committee to frame and publish laws on zoological 

 nomenclature is not to be desired. Such committee would have 



