326 



NA TURE 



\Aug. 22, 1872 



chamber when the candles went out." At such a time 

 there would be about 19 per cent, of oxygen and ri per 

 cent, of carbonic acid in the chamber. No person had 

 been in the chamber previously. " She stood five minutes 

 perfectly well, and making light of the difficulty ; but sud- 

 denly became white, and could not come out without help. 

 .She was remarkably healthy, never was ill, and was 

 troubled with no fear of the air in which she stood." 



From the air to the rain which falls through it, is but a 

 single step ; for if, as our author says, there is life and 

 death in the air, we must believe the same of the rain, 

 which collects the solids and liquids, gases and vapours 

 which float about in the atmosphere. These ingredients of 

 rain water can, indeed, be shown by chemical analysis ; 

 and by the microscope distinctions may be drawn between 

 the air of various localities, without putting the health to 

 the test. The author proceeds to describe his methods of 

 testing rain water ; but as the details of the scheme are 

 mainly of interest to chemists, we must refer any curious 

 readers to the book itself Much of the work herein de- 

 tailed was done years ago ; long, indeed, before Pasteur 

 had enlightened us as to the great reservoir of life which 

 exists in our atmosphere. In 1S52 Dr. .Smith showed 

 how complicated a fluid rain is. However carefully col- 

 lected, albuminous bodies, the remains of living creatures, 

 and minute animalcute, may invariably be detected 

 in it. "These creatures," says Dr. Smith— anticipating 

 Dr. Frankland's aphorism, " Ohne Phosphor gar kein 

 Leben " — " arc sufficient of themselves to show the 

 existence of phosphates, whilst sulphates and lime may 

 be readily obtained. In examining the Thames water 

 I often found that the readiest way of collecting 

 phosphates and magnesia was to wait for the animalcules 

 to do it." 



Through the kindness of a number of gentlemen, Dr. 

 Smith was enabled to make numerous collections of rain 

 w.atcr from as far north as the Hebrides and as far west 

 as Valentia. The results of the samples of the analysis 

 may be thus briefly summarised : — The rain over the sea 

 contains chiefly common s.alt, which crystallises clearly; 

 but it also contains sulphates, and in larger proportion to 

 the chlorides than is found in sea water. The amount 

 of these sulphates increases inland before large towns 

 are reached. They are to be regarded as the 

 measure of the products of decomposition, the sul- 

 phuretted hydrogen from putrifying organic compounds 

 becoming oxidised in the atmosphere. Within certain limi- 

 tations, they may be taken as an index of the amount of 

 sewage in the air. We accordingly find in the large 

 towns the amount of the sulphates is greatly increased, 

 owing to the combustion of the sulphur in coal, as well 

 as the decomposition of organic matter contained in 

 protein substances. When the sulphuric acid increases 

 more rapidly than the ammonia, the rain-water becomes 

 acid, and when the amount of this free acid reaches two 

 or three grains in a gallon, or forty parts in a million, 

 there is no hope for vegetation in a climate such as we 

 have in the northern parts of this country. These free 

 acids are not found with certainty where combustion or 

 manufactures are not the cause. The amount of ammonia- 

 cal salts in the rain water increases with the number of 

 towns in the district. This ammonia comes partly from 

 the coal, and partly from the decomposition of albuminoid 



substances, which, indeed, may also bs detected in the 

 rain water. It is very interesting to compare the relative 

 purity of the atmospheres of our cities and large towns, as 

 determined by this method of air-washing. Upon the 

 whole, that of London appears to be the best, and that of 

 Glasgow decidedly the worst. Calling the amount of sul- 

 phuric acid in sea air 100, the average amount in that of 

 London is 352, and in that of Manchester 513. In Glas- 

 gow the amount of ammonia is 150, in London it is 

 115 ; the amount of albuminoid ammonia in London air 

 is only 109, whereas in Glasgow it is more than twice that 

 amount, viz. 221. These analyses shov unmistakably in 

 wh U the evil of overcrowding consists ; and it is with this 

 subject on which he is thus led to speak that Dr. Smith 

 closes his book. We commend his remarks to our City 

 Improvement officials : — " Let those courts, alleys, and 

 streets, which show the greatest mortality and the worst 

 air, be destroyed or improved, without foolish mercy. 

 There is a want of willingness to pull down dangerous 

 property, but a readiness to rush forward to save the life 

 of the greatest criminals. Reason is out of the question 

 in the matter. We are misled by an uneducated feeling. 

 We like to save property, forgetting that deadly weapons 

 and poisons are subject to peculiar laws, and their indis- 

 criminate use is forbidden to the nation. And houses that 

 produce death are not property ; as well might a man claim 

 his debts as such. If a man sells unwholesome meat 

 the law interferes ; if he sells the use of a room with 

 fever in it, the nation seems not to complain. Officers of 

 health point out such places, but the public still refuse to 

 destroy them, and great numbers are slain annually by 

 legal methods, while strict methods are taken to prevent 

 a few annually being killed by arsenic— a death more 

 agreeable than the lingering misery in the lower parts of 

 our crowded towns. I know that the lowest classes living 

 in poisoned houses die from other causes than bad air ; 

 but 1 am speaking of air at present, and that is one of 

 the causes. The time must come — and the sooner the 

 better — when it shall be enacted that no land shall con- 

 tain more people per acre than we know by experience 

 in sever.al places can live heaUhily thereon. The same 

 thing must be said regarding houses, although these are 

 more difficult for governments to deal with, because of 

 the degradation of some of the population. Still the 

 limitation must be attained, and for that we must strive." 



T. E. Thorpe 



THE IRON AND STEEL INSTITUTE 



'X'HE Fourth Annual Provincial Meeting of the Iron 

 A and Steel Institute was held recently (August 6th 

 to 9th inclusive) in Glasgow, under the presidency of Mr. 

 Henry Bessemer, and it has been, if it were possible, even 

 more successful than any of the previous reunions, fur- 

 nishing thereby the best proof that such an association 

 actually was a desideratum, and of the hearty co-operation 

 which its establishment has called forth, from all inte- 

 rested directly or indirectly in the development of the 

 Iron and .Steel manufactures of Great Britain. 



Since the three previous meetings were all held in the 

 iron districts south of the Tweed, it is the more gratifying 

 on this occasion to find that the first meeting of the Insti- 

 tution in Scotland should have turned out so eminently 

 successful, and so marked by the hearty welcome with 

 which Scotch ironmasters have received their Southern 



