VOL. XXIX.] PHILOSOPHICAL TRANSACTIONS. '- 8^ 



these 8 years past, has now put it out of all suspicion and doubt; since the 

 operation having been performed on persons of all ages, sexes, and different 

 temperaments, and even in the worst constitution of the air, yet none have been 

 found to die of it ; where at the same time it was very mortal when it seized the 

 patient the common way. of which half the affected died. This the Doctor at- 

 tests from his own observation. 



He next observes, that such as have this inoculation practised on them, are 

 subject to very slight symptoms, some being scarcely sensible they are ill or sick ; 

 and, what is valued by the fair, it never leaves any scars or pits in the face. 



The method of the operation is thus : choice being made of a proper con- 

 tagion, the matter of the pustules is to be communicated to the person proposed 

 to take the infection ; whence it has, metaphorically, the name of incision or 

 inoculation. For this purpose, they pitch upon some boy, or young lad, of a 

 sound healthy temperament, that is seized with the common small-pox (of the 

 distinct, not confluent kind) on the 12th or 13th day from the beginning of his 

 sickness ; they with a needle prick the tubercles (chiefly those on the shins 

 and hams) and press out the matter coming from them into some convenient 

 glass vessel, or the like, to receive it ; and it is proper to wash and clean the 

 vessel first with warm water : a convenient quantity of this matter being thus 

 collected, is to be stopped close, and kept warm in the bosom of the person 

 that carries it, and, as soon as may be brought to the place of the expecting 

 future patient ; who being in a warm chamber, the operator is to make several 

 little wounds with a needle, in one, two or more places of the skin, till some 

 drops of blood follow, and immediately drop out some drops of the matter in 

 the glass, and mix it well with the blood issuing out ; one drop of the matter is 

 sufficient for each place pricked. These punctures are made indifferently in 

 any of the fleshy parts, but succeed best in the muscles of the arm or radius. 

 The needle is to be a three edged surgeon's needle; it may likewise be per- 

 formed with a lancet : the custom is to run the needle transverse, and rip up the 

 skin a little, that there may be a convenient dividing of the part, and the mixing 

 of the matter with the blood more easily performed; which is done, either with 

 a blunt stile, or an ear-picker: the wound is covered with half a walnut-shell, 

 or the like concave vessel, and bound over, that the matter be not rubbed off" 

 by the clothes. The patient is to be careful of his diet. In this place the 

 custom is, to abstain wholly from flesh and broth for 3 or 4 weeks. This 

 operation is performed, either in the beginning of the winter, or in the spring. 

 Some, for caution, order the matter to be brought from the sick by a 3d person, 

 lest any infection should be conveyed by the clothes of the operator; but this is 

 not material. 



VOL. VI. N 



