170 



portance of some triple alloys, and on the substitution of pure iron 

 for steel in the formation of alloys. 



Some Observations on the Buffy Coat of the Blood, fyc. By John 

 Davy, M.D. F.R.S. Read April 18, 1822. [Phil. Trans. 1822, 

 p. 271.] 



The peculiar appearance which the blood sometimes assumes after 

 its coagulation, and which has been termed " buff," has been referred 

 by Mr. Hewson to its increased tenuity and slow coagulation. Dr. 

 Davy is inclined to ascribe the separation of the colouring matter 

 from a part of the coagulum, or diminished viscidity to the former 

 rather than the latter cause ; for he has remarked that blood drawn 

 in several inflammatory diseases coagulates with its usual rapidity, 

 and yet forms the buffy coat : its specific gravity also rather exceeds 

 than falls short of that of healthy blood. 



Dr. Davy next adverts to the opinion that the age of the morbid 

 adhesions, which on dissection are often found to connect together 

 serous membranes, is proportionate to their strength : but as he has 

 found strong adhesions formed in twenty-four hours between surfaces 

 of the pleura, in consequence of inflammation artificially excited ; and 

 as he has remarked a peculiar tenacity in the coagulable lymph of 

 the blood, enabling it to be drawn out into bands and fibres, which 

 become solid and opake, and thus represent ordinary adhesions, he 

 is inclined to doubt the correctness of the above opinion. 



Lastly, the author mentions the supposed pouring out of serous 

 fluids into certain cavities, after death ; and cites experiments to 

 show that, under ordinary circumstances, no such effusion or exu- 

 dation of serum takes place. 



On the Mechanism of the Spine. By Henry Earle, Esq. F.R.S. 

 Surgeon to the Foundling, and Assistant Surgeon to St. Bartholo- 

 mew's Hospital. Read April 25, 1822. [Phil. Trans. 1822, 

 p. 276.] 



In examining the structure of the vertebrae in different animals, the 

 author was particularly struck with the mechanism of the spine and 

 spinal canal in birds, by which great motion is gained in the neck 

 without injury to the spinal marrow. The cervical vertebrae in birds 

 vary from 9 to 24 in number ; they differ considerably from each 

 other, and are articulated by complex joints, in some respects resem- 

 bling the articulation of the olecranon with the humerus in the human 

 subject, but admitting also of lateral motion. The varying positions 

 of the articulating surfaces are favoured by the interposition of a car- 

 tilage, adapted to the surface of each bone, and inclosed between 

 reduplications of sinovial membrane ; each joint is thus double, and 

 resembles the articulation of the human lower jaw. The canal of 

 each vertebra is contracted in the centre, and enlarges above and 



