28 Influence of Atmospheric Temperature 



mains of birds in formations antecedent to the tertiary series, 

 was b}^ no means satisfactorily determined, and in consequence 

 of the striking approximations to birds, lately discovered by me 

 to exist in the Pterodactyles,* I had so much the more reason 

 for believing fossil birds to be confined to the tertiary strata. 



I was therefore not a little surprised at the sight of a slab 

 of Glarus slate, lately sent me for examination by the kindness 

 of M. Arnold Escher von der Linth of Zurich. This rock has 

 been rendered remarkable by its fossil fishes, and by its Che- 

 Ionia Knorrii ; it was formerly, on account of its petrographical 

 characters, considered of great age, but subsequently, from 

 the nature of the fossil fishes it contains, has been determined 

 by Agassiz to be a formation of the age of the chalk. On the 

 slab forwarded to me, T found the remains of the skeleton of 

 an animal, which can have been nothing else but a bird ; and 

 this view is placed beyond all doubt by the distinctly preserved 

 bones of the wing and the foot. The feet cannot have been 

 adapted for wading, and the bird cannot, therefore, have be- 

 longed to the GralloB ; it would seem rather to have been one 

 of the PasserinWy and it must have had the size of a lark. — 

 (From Leonhard and Bronn's Jahrbuch^ 1839.^ 



On the Influence of Weather in Relation to Disease. 1 . Tempe- 

 rature ; 2. Moisture ; 3. Pressure ; 4. Electricity.'^ 

 1. Temperature of the Atmosphere. — The influence of tempe- 

 rature is the most familiar of the conditions we have to examine, 

 and that which has been chiefly studied ; in its direct effects on 

 the body, and indirectly through the diseases of climate. As 

 respects the former, it seems certain that changes^ sudden or 

 frequent, are principally concerned in these restdts.f The 



* In regard to the air-cells in the bones, see the Jahrbttch/iir Mhieralogiey 

 1837, p. 316 ; and respecting the structure of the anterior extremities, the 

 same work, 1838, p. 668. 



t This interesting article \vc have taken from a volume of rare merit lately 

 published by an accomplished physician, entitled " Medical Notes and Reflec- 

 tions by H. Holland, M.D. F.R.S., Physician Extraordinary to the Queen," 

 &c. &c. 8vo, p. 628. Longman, Orme, & Co., London. — Editor. 



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cratet. 



