SMALL-POX. 



of the heels of a horfe, of which the cow-pox has recently 

 afforded an example, has led fome fpeculators to the more 

 probable conjeaure, that the poifon of fmall.pox may have 

 been communicated to the human from fome domellicated 

 animal. The camel has been fuggefted : but it was for- 

 gotten, that, though Arabia was the country from which 

 Europe probably received the contagion ; yet that that 

 country appears to have received it from the moft eaftern 

 nations, by its early commerce, among whom it had pre- 

 vioufly exifted from remote antiquity. (See Moore's in- 

 tereftmg " Hiitory of the Small-pox," 1815.) At pre- 

 fenl we can only attend to the operation of this contagion, 

 and inveftigate its qualities from the eifedls which it pro- 

 duces. 



It is evident, that the contagion of fmall-pox is capable 

 of being communicated, and of exciting the difeafe in others, 

 both b^ the aftual contaft of the fluid of the pultules, and 

 the dried cruHs, and by difFufion in a ftate of folution in 

 the atmofpheric air. It may be alfo fixed and adherent 

 to various fubftances, fuch as woollen, hnen, cotton, and 

 other materials of clothing, as well as to wood, and other 

 articles of furniture ; from which alfo it may exhale in a 

 itate of vapour. Whence a perfon may be infcfted, with- 

 out aftual contaft either of the difeafed, or of fom'ites, that 

 is, of infefted fubftances. We have already ftated, how- 

 ever, at great length, under the article Contagion, (which 

 fee,) the proofs and experiments by which it is rendered 

 manifelt, that the influence of this, and probably of moft 

 other contagions, by diffufion m the atmofphere, is limited 

 to a very fmall diftance from the fource of infeftion. We 

 refer efpecially to the experiments of Dr. O'Ryan, of Mont- 

 pellier, upon that fubjeft, which are related in the article 

 jult referred to. See alfo Dr. Haygarth's Plan for the 

 Extermination of Small-pox in Great Britain. 



One property of the contagion of fmall-pox, which it 

 poii'effes in common with tlie contairion of meafles, fcarlet 

 fever, and chicken-pox, but which does not belong to the 

 contagion of gaol-fever, or typhus, nor to that of the plague, 

 nor to the chronic contagious maladies, fyphilis, and fca- 

 bies, is its power of afEefting the conftitution but once during 

 the life of the individual. The occurrence of the difeafe, 

 under the mildeft or the moft fevere form, equally renders 

 the body incapable of receiving the difeafe again. This is 

 the general fa6t ; but in regard to none of thefe eruptive 

 fevers can it be affirmed, without many exceptions : and 

 the fmall-pox prefents many anomalies in this refpeft. The 

 extreme rarity of a fecond attack of fmall-pox was no- 

 ticed by the Arabian writers ; and their admidion of fuch 

 a faft would fcarcely be admitted as a proof of its occur- 

 rence, fince they deemed the fmall-pox and meafles to be 

 but varieties of the fame difeafe. They attempted to explain 

 the occafional recurrence of the difeafe upon their abfurd 

 theory of its origin, fuppofing that the whole of the men- 

 ftrual blood, which contaminates the child, is not thoroughly 

 depurated and expelled by the firft attack. Even Boer- 

 haave feems to have believed, that the di/lina fmall-pox 

 did not invariably fecure the individual from a fubfequent 

 attack of the confuent form ; though the latter eft'eftually 

 prevented a recurrence. (See his Praxis Medica, § 1381.) 

 This, however, is not confiftcnt with faft : for fome of the 

 moft formidable and even fatal attacks of yiYow^/ fmall-pox 

 have occurred in perfons previoufly much pitted and dif- 

 figured by the difeafe. It will not be neceflary to enter, 

 in this place, into a very minute detail of the cafes of fecon- 

 dary fmall-pox : it will be fufhcient to ftate the fad, and 

 to refer to fome of the authorities on the fubjeft of recent 

 4ate, fince the diftindlions between chicken-pox, and the 



modifications of Imall-pox, have been fully eftablifhed. 

 The celebrated Dr. De Haen has related feveral very clear 

 inftances of fecond fmall-pox, which occurred in his own 

 praftice. One young man, a ftudent of law, received the 

 contagion twice within three years ; the firft attack left 

 him pitted, and the fecond proved fatal. ( See his Ratio 

 Medendi, p. ix. ch. 7 : alfo his Epift. Apolog. Refponf. 

 ad B. L. Tralles. ) One of the moft ftriking cafes of this 

 fort, is that of Mr. Langford, whole countenance was 

 " remarkably pitted and feamed" by a former malignant 

 fmall-pox, " fo as to attraft the notice of all who faw 

 him :" yet at the age of fifty, he was attacked again with 

 confluent fmall-pox, which proved fatal to him, and to an- 

 other member of his family, five of whom received the in- 

 feftion from him. (See Memoirs of the Medical Society 

 of London, vol. iv. ) A cafe of diftinft recurrence of 

 fmall-pox is related by Dr. Laird, in the Edinburgh Jour- 

 nal, already referred to ; another by Dr. Bateman, in the 

 Medico-Chirurgical Tranfaftions, vol. ii. p. 31 ; and Mr. 

 Ring has eoUefted a great number, to the amount of fixty 

 or feventy, in his Tieatife on Cow-pox, and in various 

 numbers of the London Medical and Phyfical Journal, 

 efpecially in volumes 12, 14, and 15. We may add, that 

 the recurrence of meafles, in feveral cafes, has been lately 

 authenticated, by the firft medical authority now living, 

 (we mean by Dr. BaiUie,) in a paper pubhihed in the third 

 volume of the Tranfaftions of a Society for the Improve- 

 ment of Medical and Chirurgical Knowledge. The fcarlet 

 fever appears to be alfo fubjeft to the fame anomalies occa- 

 fionally. The exceptions, however, are rare in all thefe 

 eruptive fevers, and the general rule will ftill hold good. 

 Yet the confiderations of thefe exceptions flionld remove 

 our furprife, that the cow-pox fliould not invariably fecure 

 the conftitution from a fubfequent feizure by the fmall-pox ; 

 fince its influer.ce on the fyftem is commonly lefs confider- 

 able, than that of the mildeft diftinft fmall-pox. We be- 

 lieve, however, that the fmall-pox, which, under the excep- 

 tions, has been occafionally feen to follow the cow-pox, has 

 always been much mitigated by the prior operation of the 

 vaccine virus, both in the violence and duration of the 

 fymptoms, and that it has never, in thefe cafes, terminated 

 fatally. 



It appears, from the preceding hiftory of the fymptoms, 

 that the fafety and danger of the fmall-pox depends almoft 

 entirely upon the fmaller or larger number of the pultules : , 

 it becomes very important, therefore, both with a view to 

 the prevention and to the treatment of the difeafe, to in- 

 veftigate the origin of this difference in the eruption, and 

 in the fymptoms which accompany it. 



From the difference in the appearance, confiftence, colour, ; 

 &c. of the matter produced, as well as in the number and 

 form of the puftules, and from the various degrees of fever, 

 and other fymptoms, whicli accompany the different fpecies 

 of fmall-pox, it might be readily fufpefted, that the con- 

 tagion itfelf was different. Experience, however, has com- 

 pletely refuted this fuppofition : for there are innumerable 

 inftances of the contagion, arifing from a perfon affefted 

 with the mild and diftinft fmall-pox, producing the con- 

 fluent kind in others ; and, on the other hand, it is ex- 

 tremely common to fee the diftinft kind produced by ex- 

 pofure to the contagion arifing from a perfon affefted with 

 the worft confluent fmall-pox. The praftice of inoculation 

 has ftill farther dcmonftrated this fact. For the fame 

 matter was not unfrequently obferved to produce in one 

 perfon the diftinft, and in another the confluent fmall-pox. 

 And in order that no time fliould be unneceffarily loft, 

 where perfons have been in the moft imminent danger from 



complete 



