PKEVENTION OF PLEUliO-PNEUMONIA. 191 



disclose the existence of disease, and compensate them for all 

 that are slaughtered, we shall do all the necessary internal 

 work, and the country might be returned under a clean bill of 

 health in less than six months. Again, if we suppose we are 

 ■conveying the virus to a healthy animal among others, how can 

 we reconcile the statement that others will not become infected ? 

 The opinions expressed by the Secretary of Legation in Holland, 

 that inoculation may be practised in non-infected places with 

 safety, are the result of a loose and vague mode of reasoning. It 

 is quite patent to all, that if we introduce the matter of contagious 

 disease, we produce a contagious malady ; if we possessed the 

 virus it would be dangerous to carry it about, and quite on a par 

 with keeping alive one of the worst forms of disease. It is 

 fortunate for us we possess it not, and it will be still more 

 profitable to us if we cease to dabble in scientific muddles, and 

 take to common sense means of preventing disaster, which are 

 not only well understood and sanctioned by ample experience, 

 but are also at our very fingers' ends. 



ON THE EFFECTS PRODUCED ON TREES AND SHRUBS 

 BY SMOKE FROM PUBLIC WORKS. 



By Robert Hutchison of Caiiowrie, Kirkliston. 



[Premium — The Medium Gold McdalJ] 



The rapid expansion of the commercial and manufacturing 

 activity of the United Kingdom, during the past quarter of a 

 century, in nearly every part of the country, and the consequent 

 erection and enlargement of public works of various descriptions, 

 — while of paramount importance to the social well-being and 

 industry of teeming thousands of tlie population, — are, neverthe- 

 less, inseparably connected with the origin of latent evils which 

 affect in a greater or less degree, according to circumstances, in 

 the vicinity of such manufactories, the amenity and salubrity of 

 the district, the growth and health of the adjacent crops witliin 

 their influence, and the vitality of vegetation generally from the 

 tiniest blade of grass to the tree of giant dimensions. 



These pernicious influences are of various kinds and degrees, 

 affecting the atmosphere, the soil, the water suppty, or, it may 

 be, all these together. For simplification they may be classed 

 under the following heads: — 



\st, Pollution of water-supply, and food of plants by chemical 

 discharges from public works into open drains, water courses, or 

 rivers. 



2nd, Saturation of the soil from deleterious matters filtrating 

 into it, and its consequent destruction for plant-life. 



