April 15, 1909J 



NATURE 



produced is proportional to the quantity of gas required. 

 This is only partly true, as actually the temperature of 

 the fire does not vary as quickly as the load on the engine 

 may vary, and although there may be a considerable fall 

 in the load, there is usually heat enough in the fire to 

 produce more steam than is then desirable. If this excess 

 of steam continues, it not only causes an excess of carbon 

 dioxide to be formed, but it damps down the fire. Then, 

 when the load is increased suddenly, the temperature of 

 the fire is not high enough to develop the power required. 

 Some makers of suction plants try to get over this difficulty 

 by having regulating valves worked by the engine, by 

 means of which the admission of steam to the fire is 

 governed by the engine. Some merely allow a vent in 

 the vapouriser for the excess of steam to escape when the 

 load is reduced, some make no special provision at all, 

 while others use the suction of the engine to draw water 

 into the vapouriser in very small quantities, just enough 

 at each suction-stroke to give the steam required for the 

 quantity of gas to be consumed. This can only be done 

 provided the vapouriser flashes the water into steam ; if 

 the vapouriser holds a body of water, as in a boiler, steam 

 is given off continuously, and although there might be a 

 governing of the feed-water, the quantity of steam pro- 

 duced would not be governed. J. Emerson Dowson. 

 {To he continued.) 



THE SCOPE OF EUGENICS. 

 T^HE first edition of the Robert Boyle lecture " On the 

 Scope and Importance to the State of the Science of 

 National Eugenics," delivered by Prof. Karl Pearson in 

 1907 before the Oxford University Junior Science Club, 

 being out of print, the author has re-issued the same 

 through Messrs. Dulau and Co. as the first of a " Eugenics 

 Laboratory Lecture Series," intended to place the purport 

 of the investigations conducted in that laboratory before 

 the public in a simple form. The series should serve a 

 useful purpose, as many of the original memoirs are some- 

 what repellent even to a reader of rather more than average 

 intelligence owing to the use of highly specialised statistical 

 methods. A translation of the lecture into German, by 

 Dr. H. Fehlinger, has been published by, the firm of 

 Teubner (Leipzig and Berlin) in the Archiv fiir Rassen- 

 tind Gesellschafts-Biologie. 



In the present lecture Prof. Pearson gives in brief the 

 whole eugenics argument. " The Darwinian hypothesis 

 asserts that the sounder individual has more chance of 

 surviving in the contest with physical and organic environ- 

 ment. It is therefore better able to produce and rear off- 

 spring, which in their turn inherit its advantageous 

 characters. Profitable variations are thus seized on by 

 natural selection, and perpetuated by heredity." If these 

 ideas apply to the case of man, " we must have evidence 

 (i) that man varies ; (2) that these variations, favourable 

 or unfavourable, are inherited; (3) that they are selected." 

 On the first head special evidence is. hardly necessary; our 

 own eyes afford evidence day by day that man varies, but 

 there is plenty of definite knowledge also as to the amount 

 and magnitude of variation. There is similarly a 

 growing mass of evidence that such variations are not 

 mere individual fluctuations, but are heritable. On the 

 third head., however, the evidence is weaker and somewhat 

 conflicting. In the population at large, natural selection 

 appears to be operative to a greater or less extent, as we 

 find that the age at death is inherited. It would be quite 

 possible, however, for that selection to be ineffective if 

 the weaker stocks nevertheless survived to a sufficient 

 age to reproduce their kind as freely as the stronger 

 stocks, and this seems to be the case to a large extent. 

 The families of deaf-mutes, the tuberculous, and the 

 mentally defective are as large as those of normal in- 

 dividuals, and the lower we go from one social grade to 

 another the higher does the fertility rise. In these facts 

 lies the stimulus to possible action directed towards the 

 betterment of the race, negatively by placing hindrances 

 in the way of the reproduction of the hopelessly unfit, 

 positively by creating an altered tone and public spirit 

 which may lead to a more normal and less restricted re- 

 production of the prosperous and the intellectual classes. 



If one sentence may be cited with special approval, it 

 is a statement near the commencement of the lecture : — • 

 " Our science does not propose to confine its attention to 

 problems of inheritance only, but to deal also with problems 

 of environment and of nurture." The improvement of the 

 environment is as much a method of improving the quali- 

 ties of future generations as the method of selection, not, 

 of course, because somatic variations are heritable (which 

 we do not believe that they are), but because the improve- 

 ment of the environment endures. In so far as housing, 

 education, and the treatment of the diseased are improved 

 in this generation, the next starts from a fresh basis. 

 Eugenic and eugeic methods should aid each other, and 

 racial improvement be based on care of both the seed 

 and the soil. Hitherto the methods have been too often 

 treated as if they were opposed. 



SCIENTIFIC WORK OF THE LOCAL 

 I GOVERNMENT BOARD. 



THIS report' of the Local Government Board is the 

 first to be submitted by Dr. Newsholme, and in the 

 introduction he pays a graceful tribute to the work of 

 the retiring principal medical officer, Sir William Power. 



The vaccination returns show a slight increase in the 

 percentage of births vaccinated and of infants exempted 

 under certificates of "conscientious objection." 



In the appendix on auxiliary scientific investigations 

 carried out for the Board, Dr. Klein has continued his 

 studies on immunity in plague, and shows that a_ watery 

 extract of the liver and spleen of a rabbit which has 

 recovered from an attack of plague possesses curative 

 properties. 



Drs. Andrewes and Gordon contribute a report on the 

 defensive mechanisms of the body against infection by the 

 pyogenic cocci, and, while admitting that the chief means 

 of defence is a phagocytic one, conclude that the bacterio- 

 lytic power of the body fluids is bv no means negligible. 

 ■ Dr. Andrewes has also investigated the micro-organisms 

 present in sewer air, with the result that the bacteria of 

 sewage are to be found in the air of sewers and drains, 

 and that therefore sewage in certain circumstances gives 

 up its bacteria to sewer and drain air, though such bacteria 

 ordinarily form but a small proportion of those present in 

 sewer air. So far, the organisms detected are not m 

 themselves known to be prejudicial to health, but their 

 presence suggests that the more harmful sewage-borne 

 microbes mav likewise gain access to sewer air. _ 



Dr Savage submits a report dealing with the bacterial 

 contamination of milk as obtained from healthy cows, and 

 with the examination of milk samples obtained from cows 

 suffering from an inflammatory disease, garget (mastitis), 

 of the udder. In another report he details the results 

 obtained in an examination of the intestinal contents of 

 domestic animals for bacteria belonging to the Gaertner 

 croup— organisms which cause certain outbreaks of meat 

 poisoning. From three bullocks and six pigs the results 

 were negative, but from a calf numerous organisms 

 belonging to this group were isolated. 



Of late the view has been gaining ground that acute 

 rheumatism is a microbial disease, and various organisms 

 have been described bv investigators. Dr. Horder con- 

 tributes a renort on the subject, but his results are mainly 

 negative, and further research is evidently called for. 



The action of the Streptococcus faecalis and of its 

 chemical products has been investigated by Dr. Sidney 

 Martin. The organism is capable of producing various 

 disease conditions in man, such as cystitis and septicnemia. 

 Preliminary experiments on the toxin of the microbe 

 suggest that the main poisonous product is an endotoxin. 



In an appendix Dr. Blaxall and Mr. Fremlin record 

 experiments on the effect of cold on the potency of vaccine 

 lymph, and show that a temperature of -180° C. has no 

 effect, and that lymph stored at -5° C. for a year suffered 

 no diminution in potency. 



It will thus be seen that the volume contains papers of 

 considerable importance in scientific medicine and hygiene. 



R. T. H. 



1 Th;rtv-si«t'i Annua' Reoort of the Loral Gover-ment Board, 1906-7. 

 Supplement containing Ihe Report of the Medical Officer for 1906-7. 



NO. 2059, VOL. 80] 



