Mabch 1, 1894.] 



KNOWLEDGE 



59 



simple experiments which can only be interpreted in one 

 way ; but the results which the statician offers us are 

 frequently the outcome of many causes acting concurrently. 

 It may be that sewage poison has but little effect on those 

 who live an active and out-of-door life, while on the town- 

 liver and the sedentary worker it produces a depressing effect, 

 which predisposes him to the attacks of zymotic disease. 

 It is certain that the small amount of organic matter in 

 sewage air is easily detected by the nose, and with some a 

 strong smell of decomposing animal matter will even 

 leave a taste in the mouth, which may be detected for 

 hours or even days ; this is especially the case with those 

 who are not accustomed to such effluvia. 



ilr. Laws found that the amount of carbonic acid gas in 

 sewage air is, on the average, a little more than double that 

 which is generally to be found in the upper air. What 

 may be called the normal quantity of carbonic acid gas 

 in the upper air is -04 per cent. 'Sir. Laws found that in 

 the King's Scholars Pond sewer the amount of carbonic 

 acid gas varied from -014 as a minimum to 1(504 as a 

 maximum, and that the average quantity was -0918 per 

 cent. 15ut this quantity of carbonic acid gas is not suffi- 

 cient of itself to produce unpleasant effects when breathed. 

 Dr. Angus Smith states that he found -1 per cent, in the 

 air of a well-ventilated soda-water factory in Manchester, 

 and it was believed to produce no bad effects on the 

 workers. But, as Messrs. Harold Wager and Auberon 

 Herbert show in a little book recently published by 

 Messrs. Williams and Norgate, entitled " Bad Air and 

 Bad Health," when in a crowded room the amount of 

 carbonic acid gas arising from respiration reaches -08 per 

 cent, the air becomes disagreeably close, and an unpleasant 

 odour is experienced which gives rise to headaches. They 

 believe and endeavour to show that this is caused by the 

 organic impurities expired from the lungs ; but the residual 

 differences which give rise to the remarkably different 

 physiological effects of the bracing air of mountains and 

 the seaside, as compared with the close air of cities, remains 

 almost as much a mystery as it was to the early chemists, 

 who could detect no sensible difference on analysis. 



M. Ch. Fere, who has written a remarkable work on 

 the " Pathology of the Emotions," has brought together 

 many facts tending to prove that the emotions have an 

 intimate connection with liability to infectious diseases. 

 He quotes some curious statistics with respect to the 

 facility with which weak-minded persons succumb to 

 acute diseases, and endeavours to prove that depressing 

 emotions have an action on the development of tuberculosis, 

 phthisis, and especially on puerperal infection — his theory 

 being that the depressing emotions have an action on the 

 development and healthy activity of the leucocytes or 

 white globules, whose chief mission is to protect the 

 organism against the invasion of microbes. 



The following is the sort of e\"idence referred to : 

 M. Hervieux, resident medical officer of a lying-in 

 hospital, made notes as to the effect of the moral emotions 

 on puerperal infection, and found a large number of cases 

 in which young women, in a fair way towards recovery, 

 had taken a chill and become mortally ill after a visit or 

 untimely -reproaches from their mother or relatives, or 

 after the agitation or perplexity occasioned by their 

 resolving to abandon their child — unfortunate girls, till 

 then doing well, falling ill on carrying out the resolution 

 and succumbing in a short time. 



If fear plays a part in the spread of zymotic disease, it is 

 evidently important to sweep away any superstitious dread 

 of conditions which may not really be dangerous. With 

 the spread of sanitary appliances there has been a wide 

 spread of sanitary theories, some of which are evidently 



no better than depressing superstitions. The improved 

 sanitary conditions have generally brought with them an 

 increase of light, cleanliness, and ventilation, but they 

 have been working concurrently with the depressing 

 influence of the fear of an unseen enemy — sewer air — which 

 was believed to bear with it deadly microbes. 



The following figures, taken from the fiftv-fourth annual 

 report of the Registrar-General, pul)lished' in 1892, show 

 how little the effect of these sanitary improvements, 

 working concurrently with such depressing superstitions, 

 and the increasing strain of modern life with its trains 

 and telephones and social discontent, has been upon 

 the number of deaths from zymotic disease, though the 

 number of deaths from all causes, per million of the 

 population per annum, has steadilv decreased from 1858 

 to 1890. 



Annial Dkath Eates from Various Causes to a Million- 

 Persons LIVING IN GrOI-PS OF Ye.VRS FROM 1858 — 1890. 



Scicn« Notes. 



There appears to be some probability of the ultimate 

 extinction of india-rubber-producing trees. It is proposed 

 to preserve existing forest and thickets, and to require that 

 collectors working a grove should plant, at the same time, 

 a certain number of trees. It is also stated, in a paper by 

 Dr. Ernst on this subject, that the primitive and wasteful 

 method of evaporating the juice over a wood fire is still 

 extensively practised, instead of the improved processes 

 now known. It would not only be a public inconvenience, 

 but possibly even a severe hindrance to certain branches 

 of scientific work, if an india-rubber famine were to occur. 



The discovery of a fault in south-west Cornwall has been 

 prophesied by Mr. Charles Da\-ison on the strength of the 

 phenomena of the Cornwall earthquakes of May, 1892. 

 He would infer that the fault will run east and west, and 

 slope to the south. Such a fault is not shown on the 

 geological survey map of the district. Mr. Davison is of 

 opinion that these shocks are the last dying movements of 

 the series of changes in relative level which have resulted 

 in the formation of the English Channel. A cursory 

 glance at the survey map of the region, however, will 

 incline the reader to the view that the general direction of 

 the faults in Cornwall is north-west and south-east rather 

 than parallel with the Channel axis, as this view would 

 seem to require. 



