146 Researches Regarding Cholera : the Blood. [part I. 



as particles of such excessive minuteness must naturally tend to move actively for 

 some time, when the fluid containing them is subject to so much disturbance as is 

 involved in procuring and mounting specimens of it for examination. The chief 

 point of importance in regard to them is, that bodies of such a nature may occasionally 

 be detected in the blood of individuals apparently in perfect health. 



4. Fibrinous threads. — In two of the specimens of the table, delicate fibrinous 

 threads were numerous, crossing the serous spaces between the corpuscles. We have 

 observed that threads of this nature very soon disappear, and in these particular 

 preparations they were not visible after an interval of twenty-four hours. 



5. Bacteria. — Distinct bacteria were observed in no instance either as actually 

 present in the specimens immediately on their removal from the body, or as being 

 developed in them during the time in which they were retained under observation 

 — a time varying from a few days to several months. 



6. Fungi. — In only one instance were fungi developed in a specimen whilst 

 under observation ; but, as the forms which were developed in this instance were 

 those belonging to ordinary atmospheric spores, and as only one of two specimens 

 simultaneously obtained from the same individual was affected, the presumption 

 is that they were due merely to accidental contamination, and not to the presence 

 of any inherent fungal elements in the blood. 



7. Phenomena dependent on imperfections in the glass of slides and covers. — 

 It will be seen that in four specimens numerous bacteroid bodies were present, 

 which were traced to imperfections in the surface of the glasses employed to mount 

 the specimens. It may appear unnecessary to enter into any detailed discussion of 

 such appearances, but as we were for a considerable time somewhat misled by such 

 appearances, and as it seems very probable that other observers, on whose observations 

 great reliance has been placed, have been similarly misled, we consider that a brief 

 account of such fallacious appearances — which we propose to call " spectral bacteria " — 

 may not be amiss. 



In describing preparations of blood and of choleraic fluids in previous reports 

 reference has more than once been made to the appearance of " milky spots," * and 

 it was in working with such specimens that the phenomena due to slight erosions 

 of glass surfaces in contact with viscid fluids were first clearly recognized. It was 

 casually observed that the cover-glass in a particular specimen, which showed these 

 milk spots in considerable numbers, had been slightly affected with that form of 

 surface decomposition which so rapidly renders thin glass useless for microscopic work 



* Ninth Annual Sanitary Report, App. A, p. 26. 



