Oct. 30, 1879] 



NATURE 



643 



]!revailiii2 winds; what is the amount and incidence of the 

 rainfall ; and what is the percolative capacity of the soil. The 

 engineer cannot interfere with the general conditions of a climate, 



I but he may produce important changes in the immediate snr- 

 roimdings of a locality : he may modify the condition and tem- 

 perature of the soil ; he may control atmospheric damp ; he 

 may arrange for the rapid removal of rainfall, or he may cause 

 the rainfall to be retained in the soil, to be given out gradually 

 in springs, instead of passing away in torrents to flood the 



I neighbouring districts. 



Mr. Galton showedby comparing the death-rate in the model 

 ■ 'dging-houses in London with that of other districts that any 

 extraordinary degree of unhealthiness in towns is unnecessary. 



One important step in knowledge of sanitary construction is to 

 learnhow to obtain pure air in a building. What is pure air? What 

 are the impurities which make the air of a town so different from 

 the fresh air of the country? The volume of sulphuric acid 

 from coal thrown up by our fires into London air is enormous. 

 A cubic yard of London air has been found to contain nineteen 

 grains of sulphurous acid. The street dust and mud is full of 

 ammonia from horse-dung. The gases from the sewers pour into 

 the town air. Our civilisation compels us to live in houses, and to 

 maintain a temperature different from that out of doors. What 

 are the cond itions as to change under which we exist out of doors ? 

 Mr. Galton then proceeded to show that it is all but impossible 

 to maintain a supply of pure air indoors. Any ventilating 

 arrangements are only makeshifts to assist in remedying the evils to 

 which we are exposed from the necessity of obtaining an atmo- 

 sphere in our hou-^es different in temperature from that of the outer 

 air. On the other hand, means might be adopted to obtain as pure 

 air as we can. Suspended matters exist in much smaller quan- 

 tities at an altitude ; at 100 feet they are greatly diminished ; at 

 300 feet the air is comparatively pure. In Paris the air for the 

 Legislative Assembly is drawn down from a height of 180 feet, 

 so as to be taken from a point above many of the impurities of 

 the town atmosphere. That is a reasonable and sensible arrange- 

 ment, and might be asefuUy adopted in public buildings in towns. 

 In the Houses of Parliament the so-called fresh air is taken from 

 courtyards on the street level, from which horse traffic is not 

 excluded. The maintenance of the standard of purity, or rather 

 impurity, in a building, depends on ventilating arrangements. 

 Ventilation chiefly depends on the laws which govern the move- 

 ment of air, its dilatation by heat or contraction by cold ; or, if 

 ventilation is effected by pumps and fans, then upon the laws of 

 the motion of air in channels, the friction they entail, and similar 

 questions ; therefore all these are matters for careful study. But 

 when we apply the study to practice, other considerations occur. 

 It may be .'•ummed up that, whatever the cubic space, the air in 

 a confined space occupied by living beings may be assumed to 

 attain a permanent degree of purity, or rather impurity, theo- 

 retically dependent upon the rate at which emanations are given 

 out by the breathing and other exhalations of the occupants, and 

 upon the rate at which fresh air is admitted, and that, therefore, 

 the same supply of air will equally well ventilate any space, but 

 the larger the cubic space the longer it will be before the air in 

 it attains its iiermanent condition of impurity. Moreover, the 

 larger the cubic space, the more easily will the supply of fresh 

 air be brought in without altering the temperature, and without 

 causing injurious draughts. "A room warmed by an open 

 fire," Mr. Galton maintains, "is pleasanter than a room 

 warmed by hot-water pipes. A warm body radiates heat 

 to a colder body near to it. The heat rays from a flame or 

 from incandescent matter pass through the air without heating 

 it ; they warm the solid bodies upon which they impinge, and 

 these warm the air. Where the source of heat in a room 

 consists of hot-water pipes, or low-pressure steam pipes, the air 

 is first warmed, and imparts its heat to the walls. The air is 

 thus warmer than the walls. When a room is warmed by an 

 open fire, on the other hand, the wanning is effected by the 

 radiant heat from the fire, which passes through the air without 

 sensibly w arming it ; the radiant heat warms the walls and furni- 

 ture, and these impart their heat to the air. Therefore the waUs in 

 his case are warmer than the air. Consequently, in two rooms, 

 ne warmed by an open fire, and the other by hot-water pipes, 

 and with air at the same temperature in both rooms, the walls in 

 the room heated by hot-water pipes would 1* some degrees 

 colder than the air in the room, and therefore colder than the 

 walls of a room heated by an open fire ; and these colder walls 

 would therefore abstract heat from the occupants by radiation 

 more rapidly than would be the case in the room heated by an 

 open fire. And to bring the walls in the room heated with hot- 



water pipes to the same temperature as the walls in the rooms 

 heated by the open fire would require the air of the room to be 

 heated to an amount beyond that necessary for comfort, and 

 therefore to a greater amount than is desirable. Besides theoretical 

 knowledge, it is of essential importance that the sanitarj' 

 architect, builder, or engineer, should have also practical technical 

 knowledge of the subject. He should know what constitutes a 

 good material and good workmanship. It is not only the officers 

 of the army of sanitary constructors who require knowledge and 

 education, but the foremen and the labourers, each in his own 

 degree." 



Prof. Corfield's address was on Sanitary Fallacies. After an in- 

 teresting historical rhumj, he dealt with some fallacies of the pre- 

 sent day. Against all sanitary improvements whatever we find one 

 argument continually brought — that things have gone on in the 

 same way for many years, and there is no reason why they should 

 be changed, that our forefathers from generation to generation 

 lived under unsanitary conditions, and why should we not do the 

 same? that cholera, or enteric fever, or diphtheria has never 

 broken out in a place, or in a particular house, and so it need 

 not be expected ! Dr. Corfield showed how fallacious and 

 mischievous this argument is. The arguments brought forward 

 to support the spontaneous origination of the poisons of 

 typhus and enteric fevers, of diphtheria, and of cholera, 

 are most of them fallacious in the extreme, and the argu- 

 ments advanced to prove the de nrvo origination of the 

 poison of enteric fever, are of themselves sufficient to render it 

 in the highest degree improbable. They are, indeed, so weak, 

 that no one really capable of judging the value of a scientific 

 argument, could from them come to any other conclusion than 

 that the position was untenable. But a practical and very 

 serious mischief has arisen from the spread of these doctrines. 

 In the majority of ;ases no pains are taken to^destroy the excre- 

 mental discharges of patients suffering from such diseases, a 

 neglect apt to lead to very dangerous consequences. * 



"But," Dr. Corfield wenton to say, "there is still "a great 

 fallacy abroad in connection with the question of the removal of 

 refuse matters from the vicinity of habitations. People talk and 

 write as if the water-carriage system and the Conservancy 

 systems stood upon the same footing — the principal of the one 

 being the immediate removal of excretal matters from houses, and 

 that of all the others being, as their name indicates, the keeping 

 of such matters in and about the house for a certain time. The 

 one is a correct principle, the other is a false one, and it is no 

 argument at all to say that where the water-carriage system is 

 badly carried out, the result may be worse than where the 

 Conservancy system is carefully managed. In sanitary matters, 

 as well as in everything else, wt should follow correct principles. 

 If we do not, but by arguments •qually specious and fallacious, try 

 to persuade ourselves that ' practically speaking' (according to the 

 cant phraseology of the day) better results may be obtained by 

 following false principles, nothing is more certain than that by an 

 inexorable law of nature true principles will assert their position, 

 and we shall be punished for our mistake by being landed in 

 difficulties greater than we had to contend with at the outset. 

 It is a very old and often-exposed fallacy to argue against the 

 use of a thing from the abuse of it, and to argue against 

 the water-carriage system because when surface drains have 

 been called upon to do the duty of sewers, for which they were 

 not intended, and of which they are not capable, or because the 

 sewage has been turned into the water-courses, which have thus 

 become unfit to supply water for domestic purposes, is an excel- 

 lent example of this kind of fallacy." 



Dr. Corfield went on to show that water containing the least 

 quantity of organic matter must be [regarded as dangerous, and 

 that absolutely ptire water should be insisted on, as the only 

 safe form for sanitary purposes. With regard to diet tics, Dr. 

 Corfield referred to the fallacies which existed for som* time, as 

 to the dietetic value of gelatine. He could not but thiik that it 

 was a mistake to utterly condemn alcoholic liquors. 



" There are those — " he said, "and I think there always will 

 be — who cannot believe that the exquisite bouquet of the « mes of 

 France, of Italy, and of Spain is only fit to be smelt, there may 

 even l>e those who are wicked enough to insinuate that if jieople 

 do not taste them they show a lamentable deficiency in the culti- 

 yation of an important sense. He referred in conclusion to the 

 anti -vaccination fallacy, and showed that statistics arc dead 

 against it. 



Under the title of "Geology in Relation to Sanitary Science,'' 

 Mr. Alfred Haviland gave some valuable hints as to what would 

 be the practical difficulty in realising any of the dreams of a 



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