1 64 



'NATURE 



[Dec. i6, il 



I have some interesting tables, prepared for me by the kind- 

 ness of Mr. A. J. Mundy, of the Registrar-General's Office, 

 which show the remarkable sanitary results of these various 

 eflbrts. The death-rate of London in the five years 183S-43 

 was 25'57 per 1000. In the five years 1880-8411 was 2i'oi 

 per 1000 ; and the deaths from zymotic diseases, which in the 

 decade 1841-50 had averaged annually 5'29 per 1000, were 

 reduced in the years 1880-84 to 3'4 per Tooo. If, however, 

 we assume that there had been no change in sanitary conditions, 

 and therefore that the death-rate had gone on increasing accord- 

 ing to Dr. Farr's formula of increase due to density of popula- 

 tion when the sanitary conditions remain unchanged, the death- 

 rate of 1S80-84 would have averaged 26 '62 per 1000 ; that is. 

 a saving of 5'6i per 1000 has been eflected by sanitary measures. 



If upon this basis we compare the saving in life which has 

 resulted from sanitary improvements at different periods since 

 1838-42, we find that it amounted to an annual saving of 4604 

 lives during 1860-70; of 13,929 lives annually during 1870-80; 

 and of 21,847 lives .annually between 1880-S4. The main drain- 

 age works were commenced about i860, and terminated in 1878, 

 and the increase in the saving of life in these consecutive periods 

 may to some extent be taken as a gauge of the effect of the 

 gradual construction .and completion of these works. No doubt 

 this London death-rate is far too high, and is an evidence that 

 insanitary conditions still prevail all round us, that the housing 

 of the working classes is still far from satisfactory, and that we 

 are too careless about infectious disease. The Metropolitan 

 Board of Works has never had a clear field for municipal action ; 

 yet when we compare the present condition of London with 

 what it was at the Queen's accession, the Metropolitan Board of 

 Works, in spite of the disadvantages of its constitution, will 

 have a grand record to show, in the jubilee year of the Queen's 

 reign, of metropoliran improvements and metropolitan sanitation. 



The main principle which guided public administration, both 

 before and during tlie earlier years of the Queen's reign, may be 

 said to have been that of non-interference, and of allowing free 

 competition to prevail ; although, no doubt, some efforts had 

 been previously made to regulate the labour of females and 

 children in Factory Acts. 



The practical application of the knowledge derived from the 

 Registrar-General's statistics led to further investigation in 

 particular cases by such men as Dr. Simon, Dr. Buchanan, 

 Sir Robert Rawlinson, and others, and gradually caused a 

 reaction from what may be called the laissez-faire system, to the 

 spread of opinion in the direction of control over individual 

 action in the interest of the community generally ; and the result 

 was the enactment of the successive laws, for regulating the 

 sanitary condition of the people, which I have enumerated above. 



This large amount of legislation is practically little more than 

 the interpretation required by the increase of population, and by 

 the complicated exigencies of modern life, of the common-law 

 maxims, Prohibetur ne qtiis faciei in suo quod nocere possit 

 alieno ; and Sic ii/ere tuo iii alieiiiiw iioi) ladas : that is to say, 

 no man shall do anything by which his neighbour may be 

 injuriously affected, and each person must so use his property 

 and his rights as not to harm any one else. 



This common-law doctrine had become practically obsolete, 

 because there was no machinery in existence to enforce it ; and 

 the present generation inherited a legacy of misery amongst the 

 poorer classes, owing to the absence of regulations in the build- 

 ing of houses as the towns increased in size, absence of water 

 supply and drainage, and other matters which I have mentioned. 



Mr. Mundy's calculations show us what have been the general 

 results of the sanitary improvement of the nation. The death- 

 rate of 1838-42 for England and Wales was 22'07 per 1000 ; 

 that of 1880-84 was I9'62 per 1000 ; and the deaths from 

 zymotic disease, which averaged 4'52 per 1000 in the decade 

 1841-50, were reduced to 271 per 1000 in the years 1S80-84. 

 It is, however, curious to note th.tt the improvement in urban 

 districts does not appear to have kept pace with that in rural 

 districts, for it appears that whilst the deaths from zymotic 

 disease in certain urban districts have declined from 5 '89 per 

 1000 in the decade 1851-60 to 5'I2 per looo in the decade 

 1871-80, the deaths from zymotic disease in rural districts in the 

 same interval have declined from 277 to I '67 per 1000. 



In order to form an estimate of the saving of life due to 

 sanitary measures, we may assume that sanitation remained in 

 abeyance, and calculate what the death-rate, according to Dr. 

 Farr's formula, would have been in consequence of increased 

 density of population, and compare that with the actual death- 



rate ; upon this assumption we find that the sanitary improve- 

 ments only began to leil after the cholera epidemic of 1848-49. 

 In the decade 1841-50, indeed, it appears that the death-rate 

 was actually larger than that due to the increased density of 

 population. But in the following decade, the sanitary improve- 

 ments began to produce their eiTect, and this effect has gradually 

 increased. In the decade 1850-60, the annual average saving of 

 lives in England and Wales from sanitary improvements was 

 7789 ; in the decade 1860-70, it rose to 10,481 ; in the decade 

 1870-80, it was 48,443 ; and in the five years 1880-84, the 

 average annual number of lives saved by sanitary improvements 

 have been 102,240. 



The present social condition of the people affords an equally 

 striking evidence of general improvement. Food and clothing 

 are cheap ; the construction of streets and new buildings in our 

 towns are regulated ; houses are improved ; overcrowding and 

 cellar dwellings are prohibited ; the common lodging-houses are 

 controlled. Petroleum affords a brilliant light to the poor in 

 country districts which are beyond the reach of gas or of the 

 electric light, and who were formerly dependent on rushlights. 

 Water supply is rarely deficient ; removal of refuse is enforced. 

 But there remains much still to be done. Numbers of the 

 people are still crowded in wretched dwellings ; our rivers are 

 polluted and subject to floods ; our infectious diseases are not 

 properly cared for. 



The main feature of the legislation of the past half-century is 

 the recognition of the principle that when large numbers are 

 congregated together in communities, the duty of preventing 

 injury from this aggregation rests on the community ; and if this 

 principle is duly acted on, if in all aggregations of population 

 free circulation of air is encouraged by preventing the crowding 

 together of buildings ; if refuse is immediately disposed of, so as 

 to cause no injury to any one ; if pure water be provided ; if we 

 isolate infectious diseases; and, above all, if we are fortunate 

 enough to retain the blessing of cheap food and clothing, we 

 shall not transmit to our posterity a similar legacy of misery to 

 that which we inherited. 



ON THE FORMS OF CLOUDS^ 

 T~"HE object of the paper was to explain a theory with regard to 

 -'■ the principles that may have the greatest effect in producing 

 the leading cloud-forms. Neglecting occasional and exceptional 

 influences, the author stated that the causes with which his paper 

 dealt might be classed under three heads: (i) the diminished 

 specific gravity of the air when more or less charged with in- 

 visible vapour, (2) the differential horizontal motion of the atmo 

 sphere, (3) the vertical motion in the atmosphere produced by 

 the heat of the sun expanding the lower air. The first of these 

 was universally recognised as the initial cause of the cumulus, or 

 first-born primary cloud. It was produced when there was so much 

 vapour generated in the lower atmosphere that the vapour-laden 

 layer projected up within the limit of condensation. Of course 

 the vapour below this limit would itself become condensed if 

 cooled in the course of its travels. During the formation of the 

 cumulus, calm was supposed to prevail. When the atmosphere 

 was in motion, its differential horizontal movement produced the 

 first important modification. Retarded by friction and other 

 causes, the lower portion of the cumulus maved more slowly 

 than the upper, and the cloud sheared over into a slanting 

 position, and ultimately became the cumulo-stratus. A young 

 cloud was thus distinguishable from those that had travelled 

 even a short distance. In this climate large well-developed 

 cumuli, though common in summer, were seldom seen in the 

 cold season. The majority of the clouds of the first stage seen 

 here were born in warm latitudes, and, coming as travelled 

 cumuli, showed more or less the condition of the cumulo-stratus. 

 The invisible vapour was subject to this same shearing motion, 

 and far-travelled water-vapour would, on its rising, as it soon does 

 in this climate, to the height necessary for condensation, at 

 once take the shape of the stratus. In the next stratum above, 

 Mr. Glaisher's investigations in his balloon ascents showed a 

 rather rapid change to a drier atmosphere. Here were found 

 the cirro-cumulus, and cirro-stratus. The differential motion of 

 the atmosphere, though diminished, was still an important 

 agent, and produced results that were not possible in the more 

 bulky and dense clouds of the lowest range. When the sun's 

 ' Abstract of a Paper read at the Birmingham meeting, 1886, of the IJritish 

 Association, by A. F. Osier, F.R.S. Communicated by Prof. Balfour 

 Stewart, F.R.S. 



