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 NEW BOOKS, WITH SHORT NOTICES. 



Experimental Eesearches on the Causes and Nature of Catarrhus 

 ^stivus (Hay-fever or Hay-asthma). By Charles H. Blackley, 

 M.R.C.S. London : Bailliere, Tyndall, and Cox, 1873.— It is some- 

 what singular that much as has been done in the direction of discover- 

 ing what is the exact nature of the cause of hay-fever, it is yet a 

 question which can hardly be considered perfectly answered. Yet 

 certainly we cannot but say that the author of the present work has 

 done much toward its discovery, and has certainly, in our opinion, put 

 us better on the road than we were previously. Of course our readers 

 are aware that already much had been done toward the completion of 

 the theory of the pollen origin of the disease when Mr. Blackley took 

 the question in hand. But he has certainly merited great credit 

 for the ingenuity he has displayed in inventing and constructing the 

 numerous contrivances which are described in this volume, for the 

 purpose of collecting, under certain given conditions, the amount of 

 pollen present in the atmosphere. Indeed in all that relates to the 

 microscopical examination of the matter he has been at considerable 

 pains to render his conclusion irrefutable, and hence his opinions 

 deserve most careful consideration. But we think it a pity that he 

 has in many cases gone over ground which really was sufficiently 

 trampled already, that he has in dealing with the question endeavoured 

 to prove facts which might be regarded as already adequately cleared 

 up. Of course one of the great difficulties of his view of the causes of 

 this disease is the fact that several of the symptoms presented by the 

 more severe cases of the malady are not referable to the influence of 

 the pollen grains as externally irritating the mucous membrane. But 

 the author offers the following remarks which seem to us worthy 

 of consideration : — " I have found by experiment that the granular 

 matter of pollen may, by dialysis, be made to pass through membranes 

 which are thicker than those that line the air vessels and bronchial 

 tubes ; and from this circumstance I think that it is highly probable 

 that the finer particles of this matter do, in some cases, pass through 

 the mucous membrane of the respiratory passages, and by getting 

 into the circulation in this way give rise to the constitutional 

 symptoms we see developed in some cases." But Mr. Blackley here 

 has the difficulty that it is only in some cases, not in all, and that it 

 remains to be proved by him, as it is not an universal fact. Again, 

 there is the circumstance that this disease is not at all general or 

 common, a fact which we ought to expect if it was due to so universal 

 a cause as he and many others allege. His experiments relative to 

 the quantity of pollen that is taken in were most satisfactorily con- 

 ducted. But they lead us to nothing. In fact we are more than ever 

 disposed to fall back on Dr. Bostock's view, that hay-fever, as it is 

 termed, is not due to the pollen from grasses, but is simply the result 

 of heat upon some peculiar constitutions. Still, the author deserves 

 every consideration from the very extended nature of his investiga- 



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