FEEE OZONE.] 



METEOROLOGY. 



usr 



had been caught. This singular and interesting pheno- 

 menon may be frequently noticed in Derbyshire, York- 

 shire, and in some of the southern counties, where plains 

 or downs, and moderate elevations, covered with trees, 

 alternate on the face of the country. A familiar instance 

 of this action on suspended moisture is seen in our 

 gardens, during a November mist, when each twig is 

 dripping with water : this may also be noticed on the 

 edges of the hair and whiskers of any one hastily walking 

 in the open air, under similar circumstances. So uni- 

 versal is the action of the radiating power of plants, 

 that we may consider the moss, lichens, heather, grass, 

 brushwood, shrubs, and trees, as specially adapted to 

 rob the air of its suspended vapour, and thus to become 

 the chief means by which our rills, lakes, and rivers are 

 constantly fed. We may add, that the blades of grass, 

 straw, and similar objects, have been found to rank 

 amongst the best radiators of heat and electricity. Perhaps 

 from some partial knowledge of tbis fact, has arisen the 

 idea, prevalent in many country placss, that a straw- 

 wisp is an excellent "lightning conductor;" and it is 

 often employed by fanners at the gable ends of thatched 

 cottages, and on wheat and haystacks, for that purpose ; 

 whilst by others, it is, perhaps, merely added as a finish- 

 ing touch. 



Before concluding these remarks on the influence of 

 drainage on meteorological conditions, we must distinctly 

 tate that they have referred solely to local induences. 

 V>'e need scarcely observe, that fogs may be so general 

 and extensive as to cover vast areas both of land and 

 ocean surface : indeed, the major part of these islands 

 may frequently be enveloped in one general mist, which 

 even yet falls far short of those that are seen near the 

 island of Newfoundland, and in many other parts of the 

 Northern Atlantic ocean. Such proceed from entirely 

 different causes, and are due to the intermixture of cur- 

 rents of hot-moist, and cold air, which, immediately on 

 impact, cause a condensation of aqueous vapour, on a 

 scale commensurate with their extent of area. In a 

 paper read by Dr. Gladstone, before the British Associa- 

 tion in 1802, it was stated, that there was greater uni- 

 formity of distribution of fogs over the surface of the 

 sea, than on the land around the British Isles ; and 

 that certain years were decidedly more foggy than others, 

 in nearly all localities. These facts, however, do not 

 affect the truth of the observations which we have 

 made in reference to the production of local fogs and 

 mists. 



OZONK, <fec. It is but recently that the presence of 

 ozone in the atmosphere has been made a subject of 

 registration, in connection with wind and weather 

 reports : in fact, so little is known of this element (if 

 such it be), that it has rarely attracted the attention 

 which its importance as a chemical agent demands. Of 

 late years, many investigations have been made into its 

 general characters and relations ; and we may here add a 

 few facts to those already given respecting it.* 



The action of oxygen on many bodies is a matter of con- 

 stant experience, as in the case of combustion, breathing, 

 rustius, Ac. Now the results of these processes are con- 

 sidered to arise simply from the chemical union of the 

 oxygen with such bases as carbon and hydrogen, in the 

 two former instances, and with metals in that of metallic 

 oxidation. But ozone is evidently so far connected with 

 oxygen, that they are only simultaneously developed ; 

 the former having never been detected, separately, from 

 oxygen in any way whatever. The artificial generation 

 of ozone we have already mentioned at the pages pre- 

 viously referred to ; and we have also found that its effects 

 generally resemble, or are just such as those we should, 

 from our previous knowledge of the properties of oxygen, 

 expect to arise when that element enters into combina- 

 tion. But ozone, also, somewhat supplements these : 

 thus, putrefaction goes on more rapidly when free ozone 

 is present with oxygen ; it acts as an irritant on the 

 animal tissues, which oxygen does not ; and, moreover, 



Bn ante. Section on Chtmulry, p. Jli; and Jftteorolofy, p. 112J. 

 See ante, p. 276. I gee ante. p. 1178. 



I See ante, pp. 1180 and 1184. 



it seems to have an affinity to free electricity, which is 

 singularly indicative of its character. This is amply 

 illustrated during the decomposition of water by voltaic 

 electricity ; the excitation of electricity by friction, as 

 with the ordinary electrical machine, <tc. To these we 

 may add another and singular instance, which we noticed 

 during a violent thunder-storm that visited the neigh- 

 bourhood of London in the early part of September, 

 1863. Whilst watching the storm, and noting the 

 interval between the lightning and the claps of thunder, 

 a brilliant flash occurred, apparently just over the spot 

 of observation, and accompanied with a loud peal of 

 thunder. Less than half a second of time intervened 

 between the two ; hence the locality of the discharge could 

 not have been more than COO feet, if so much, in 

 distance.t Almost immediately afterwards, the air smelt 

 so strongly of ozone as to produce pain in the nostrils, 

 showing that a large amount must have been set free, 

 evidently by electrical action. Precisely the same result 

 was noticed during the storm described at page 184, in 

 the Section on Electricity : in that case, however, the 

 entire body of air in the house which was "struck," was 

 affected. These are, certainly, extraordinary instances 

 of the development of free ozone ; but others frequently 

 occur, and may be especially noticed in large towns, 

 where the smell of ozone is easily recognised, in contrast 

 with the smoke usually so prevalent in such places. 

 For instance, at certain periods of the year, we have 

 noticed, in the centre of some of the largest squares in 

 the metropolis (Russell Square, Lincoln's Inn, <fec.), a 

 strong smell of ozono, accompanied with a temporary 

 cool and refreshing air, which unscientific companions 

 have denominated, at the moment, a rich "country 

 smell." Such instances, doubtless, arise from sudden 

 down-draughts of cooler air, which open spaces fre- 

 quently permit, even in crowded neighbourhoods. These 

 facts would indicate that ozone is present continuously 

 in the higher regions of the atmosphere, when positive 

 electricity is redundant a circumstance of frequent 

 occurrence, as we have already pointed out.J Wo looked 

 with great interest for the results of Mr. Glaisher's 

 observations on the presence of ozone in the higher regions 

 of the atmosphere ; but, generally speaking, whilst they 

 noted an increased amount of this agent at great eleva- 

 tions, the indications have been so varied and uncertain, 

 as to have added but little to our knowledge of the 

 subject. 



Ihe causes and presence of free ozono are matters of 

 extreme interest in a sanitary point of view. It is re- 

 marked, that its redundancy in a free state in the air, 

 occurs chiefly with cool northerly breezes, and is attended, 

 in some respects, with a more salubrious state of the 

 atmosphere. But, whilst it evidently has the tendency 

 of purifying the air, by, perhaps, removing the animal 

 and other noxious gaseous impurities, and thus of im- 

 proving the general health of the community in respect 

 to diseases of a zymotic character such as the typhoid, 

 itc. yet a largo amount of ozono may prove extremely 

 harmful to those who suffer from irritation of the bron- 

 chial tubes, affections of the lungs, and other complaints 

 of that nature. We are, indeed, almost tempted to 

 suggest, whether the increased mortality, which fre- 

 quently accompanies north-easterly winds (so prejudicial 

 to the health of persons suffering from diseases of the 

 organs of respiration), may not in some degree be due 

 to this cause. We offer this as a suggestion only, recom- 

 mending it aa worthy of close observation to those 

 whom circumstances may place in situations for carefully 

 acquiring information on the subject. 



The detection of ozone by prepared papers and 

 powders, containing the iodide of potassium and starch, 

 has been already described. But for those who may wish 

 to become accustomed to its smell, we may also suggest, 

 that if a few sticks of phosphorus be placed in a bottle 

 containing water, so that the phosphorus may be only in 

 part covered with the liquid, and the bottle bo corked, 

 the smell of ozone may be recognised on removing the 

 cork after a few minutes have elapsed ; and an occasional 

 smelling of it, as produced after this method, will enable 



