428' Description of an annular Saw, 



ceeded even in tetanus itself, we now transfer to tetanus, 

 and perhaps to other diseases of the same kind, the practice 

 which has been inconslextably proved, in t»vo instances at 

 least, if not in three, to have been successfully employed 

 in hydruphiU)ia ? 



Almost all authors have spoken of this analogy, and 

 some have gone so far as to affirm that tetanus maybe 

 easily mistaken for hydrophobia. I confess mvsolf to be 

 of a different opinion ; being fully persuaded that no per- 

 son who has often seen both diseases could ever mistake 

 the one for the olher, and that for the foilowinc reasons; 

 lirst, in tetanus the lower jaw is imnioveably iixeS, and the 

 patient speaks by the motion of his lips only, with a hissing 

 kind of noise; — whereas in hydrophobia the lower jaw is 

 moveable to any degree ; and is in fact, in the exacerba- 

 tions, almost in perpetual motion, often resembling- the 

 action oi hawking or retching, for the purpose of bringing 

 forward and expelling the viscid saliva which constantly 

 collects about the iauces ; — and in the second place, that 

 though the swallowing of fluids may be ditiicult or im- 

 pos!il)le in tetanus, and the attempt even accompanied with 

 convulsions of the face, throat, and chest, yet the obstacle 

 is conlined to the actions connected with deglutition alone, 

 and the name, the approach, and the touch of fluids, have 

 never in my experience thrown the patient into the agony 

 of horror, distress, and despair, which is invariably wit- 

 nessed in hydrophobia. 



Asiatic Miiror, May 20, 1812. J. S. 



LXIV. Description of an anmdnr Satv, calculated to cut 

 deeper than its own Centre. By Mr. Thomas Machell, 

 Surgeon, Holsingham, near Durham *. 



Sir, — 1 TAKE the liberty to solicit you to lay before the 

 Society of Arts, &c. an instrument which I presume will 

 facilitate several operations in surgery, and which I have 

 named an annular saw. It is particularly well adapted for 

 the division of cylindrical bones, surrounded bv muscles, 

 blood-vessels or nerves, and w ilh less injury to those parts 

 than by any other instrument in present use. 



In operations upon the cranium it has the superiority 

 over the trephine, and Mr. Hay's saw, as it can be applied 



* From Transactiovs of the Sociely for the Encnuragemrnt if Arts, Manufac- 

 tures, and Commerce, for 1812. ^The gold medal of the Society was 



Toted to Mr. Machell for this communication. 



to 



