172 ADDISON, ON BLOOD-CORPUSCLES. 



The several ways, then, by which injurious matter may come 

 into contact with the corpuscles of blood are all ways or 

 avenues of fever. 



Lastly, — There are some fluids which, when mingled with 

 the liquor sanguinis, and brought into contact with the red 

 corpuscles, cause these bodies to exude or eject matter that 

 may be either prolonged into tails or float away from the cor- 

 puscles as molecular particles insoluble in the liquor san- 

 guinis [vide experiments, p. 22, ante). In these experiments 

 the liquor sanguinis is visibly disturbed by an action of the 

 corpuscles. Should any action of this sort take place in the 

 living body, any kind of matter be discharged from the cor- 

 puscles into the liquor sanguinis, and be insoluble in it, such 

 matter must appear in the fluid as minute particles; any other 

 form would be incompatible with the force and rapidity of 

 the circulation. 



In blood drawn by venesection from persons labouring 

 under fever, we have seen with the microscope multitudes of 

 molecular particles swimming in the liquor sanguinis. Two 

 cases have been published in the ' London Medical Gazette,^ 

 1841 and 1842, vol. ii. 



It is impossible to say whether or not, molecular particles 

 seen in the fluid of blood withdrawn from the living body, in 

 cases of fever, come from the red corpuscles; but the behaWour 

 of these corpuscles under the influence of certain fluids is 

 evidence upon the point not to be overlooked. 



We have said that inoculation of a poison, or a miasm of 

 the air inhaled by the lungs, may or may not produce con- 

 tagious fever ; so likewise it is not every unhealthy or putrid 

 wound, nor every degraded liquor sanguinis, that is followed 

 by fever ; and conditions which may or may not be followed 

 by the sequent cannot be raised to the rank of antecedent. 

 The ways by which poisons reach the blood, then, are not the 

 antecedents of fever. The true antecedent of contagious fever 

 must be some element of the living body ; it must be of the 

 cellular class, — of universal distribution, — and have, in a 

 measure, properties of resistance against injurious agents. 

 All these requirements are combined in the red corpuscles 

 of the blood. 



If we review the ways by which poisons may reach the 

 corpuscles of blood, in other words, the avenues of fever, we 

 shall find they may be resolved into two categories. For 

 fever from inoculation, or from respiring a poisonous atmo- 

 sphere, may occur to persons previously in good health ; 

 whereas fever occasioned bv the circulation of blood through 

 unhealthy wounds or idcerations, or from a morbid liquor 



