168 ADDISOXj ON BLOOD-CORPUSCLES. 



white cells of the blood too few in number to account for the 

 large amount of reproduced virus,— we proceed to discuss the 

 properties and circumstances of the red corpuscles of blood. 

 And here the number of special particles corresponds with 

 the usual severity of the disease, and with the large amount 

 of virus reproduced. The red corpuscles exist in blood in 

 countless millions. 



For inoculation to succeed, the inserted virus must come 

 into contact, with some of the red corpuscles of blood. The 

 point of the instrument bearing the virus must open some 

 vessel circulating blood. On the other hand, in all examples 

 of punctured wounds with a poisoned instrument, the pro- 

 bability of infection is diminished, if the flow of blood from 

 the wound be copious. If little or no blood be lost, infec- 

 tion is more sure. Sucking a poisoned wound seems, on 

 many occasions, to have prevented blood-infection. That is 

 to say, if all the blood-corpuscles which have had contact 

 with the inserted virus flow or are drawn awav, blood-infec- 

 tion does not follow ; but if some of them, infected by 

 contact with the virus, continue in circulation, they carry 

 infection with them, and communicate abnormal action to 

 the rest of the corpuscles by contact. Some explanation 

 of this kind may be provisionally admitted, — its value to be 

 determined when the other facts of the inquiry have been 

 discussed. 



Secondly, — As respects an infectious atmosphere. In the 

 lungs the corpuscles of blood come into contact with air, 

 and with the substances in solution in the air. The change 

 of colour Avhich blood experiences in the lungs is from action 

 in the red corpuscles. 



In acute pneumonia the interchange between the red 

 corpuscles of blood and elements of air is interrupted, and 

 the symptoms are general distress, exalted temperature, 

 quickened pulse, thirst, and delirium. The same symptoms 

 are features of smallpox fever. And if, in two difl'erent dis- 

 orders, a class of symptoms can, in one of them, be traced to 

 a particular element of blood, it is an argument that the 

 same element of blood stands in close relation with the same 

 symptoms in the other. 



The red corpuscles of blood are not all equally affected 

 upon contact with injurious substances. 



When observed with the microscope in contact with ex- 

 traneous fluids, some of them are seen much more altered in 

 outline and appearance than others, and some resist change 

 altogether. 



If corpuscles of blood from the same person differ in sus- 



