180 On the Microscopical Characters 



infectious, contagious, nor inoculable.* Nor does it produce a 

 pathognomonic cutaneous lesion. 



It is true, as stated by Pasteur, that children born of phthisical 

 parents may, in some instances, merely become more or less sickly, 

 while in others tubercle may be developed in different degrees at 

 various ages. But one has not to consult the statistics of con- 

 sumption in order to establish this diversity in the evolution of 

 hereditary disease. Congenital syphilis may infect the ovum, the 

 foetus at term, and the infant newly born or which has survived for 

 weeks and months. But this is not the limit of its eflfect. Massa 

 narrates cases in which the disease was developed between three 

 and eleven years of age ; Balhug, similar instances at the age of 

 sixteen ; Kosen, at eleven ; Baumes, at four ; Cazenave, at eighteen ; 

 Fournier, at twenty-five ; Zambaco, at twenty-six.f Other authors 

 cite cases which illustrate the same point. In the face of these 

 observations who will venture to say, " Thus far doth it come, and 

 no farther"? 



In concluding the consideration of the general subject here dis- 

 cussed, few will refuse to concur with the opinions expressed by 

 Dr. William Aitken. " The diseases of the lower animals," says 

 this author, " rarely form any part of the study of the student of 

 medicine. The diseases of plants are almost entirely neglected. 

 Yet it is clear that until all these have been studied, and some 

 steps taken to generalize the results, every conclusion in pathology 

 regarding the nature of diseases must be the result of a limited 

 experience from a limited field of observation." — The Medical 

 Examiner, Chicago, July 15th, 1874. 



IV. — On the Microscojoical Characters of the Sjputum in Phthisis. 

 By John Denis Macdonald, M.D., F.E.S., Stafi"-Surgeon K.N., 

 Assistant Professor of Naval Hygiene, Netley Medical School. 

 Plates LXXVIII. and LXXIX. 



It is a question whether, with all our progress in pathology, we 

 can satisfactorily diagnose incipient phthisis by the microscopical 

 characters of the sputum alone. Critically similar appearances are 

 presented in the sputum of chronic haemorrhagic catarrh, and in a 

 very frequent sequel of ordinary pneumonia. Indeed there can be 



* Bouillaud states tliat " the tuberculous virus is an Jiypotliesis wliich up to 

 the present time rests upon no exact nor trustworthy observation ; and there does 

 not exist a single instance of tuberculosis of the lungs, or of any part of the body, 

 being produced in the human species by means of specific (virulent) inoculation." 

 As to contagion, the experiments of Erdt, Villemiu, Simon, Herard, and Clarke 

 have been shown by Lebert, Nyss, Sanderson, iind Fox, to demonstrate merely the 

 irritative character of subcutaneous injections of putrid matter. 



t Lancereaux, ' Traite de la Syphilis.' Paris ; 1866. 



