IMPROVED SCARIFICATOR. 343 



ingenious and respectable medical gentleman *, who speaks 

 rery satisfactorily of its performance, and which does not 

 possess the advantage of the lancets withdrawing from the 

 wounds, they being removed with the instrument, I thought, 

 that should mine be a mistaken opinion, and that some real 

 advantage attends this method, it occurred to me that sub- 

 mitting the instrument to the Society would be applying it 

 to its best use ; as from its possessing the property of the 

 lancets withdrawing themselves, it might suggest some ideas 

 for farther improvement. 



I am, sir, 



Yours obediently, 



JOHN FULLER. 



Description of the Engravings of Mr. John Fuller's Explanation of 

 scarificator, Plate IX. the P ,ate ' 



Pigs. 3, 4, 5, and 6, are sections of this instrument, 

 taken in different positions, to explain its interior mecha- 

 nism ; fig. 3, is a plan of the lancets, the top of the box be- 

 ing removed to show them ; fig. 4, is a section through the 

 centre of the box ; and fig. 6, the same, but taken in the 

 opposite direction. 



The lancets a a, 4, 5, and 6, are fixed upon two small 

 arbors mounted parallel to each other across the box ; the 

 lancets are so arranged on the arbors, that those upon one 

 arbor are placed in the intervals between the lancets fixed 

 upon the other; the arbors are placed near the top of- the 

 box, and the lancets act through clefts cut in the lid, (as 

 shown in figs. 4, and 6,) when the arbors are turned round ; 

 this is performed by a pinion upon each arbor, receiving 

 motion from two toothed sectors, A B, fig. 5, which are also 

 caused to act together by the teeth on their edges ; they are 

 fixed upon two parallel spindles CD, which extend across 

 the box ; the sector A, has a lever or handle attached to it, 

 and coming through the bottom of the box, and by pulling 

 this, the scarificator is wound up ready for action. The 

 power is given by two horseshoe springs, ee, figs. 3 and 6, 

 one end of each is screwed upon the bottom of the box, and 

 the other acts in a notch //, in each sector, so as to press 



* SeeJourn. vol. xxvii, p. 124. 



those 



