222 EDWARD JENNER 



municated to them. I have inoculated a great number of 

 females in that situation, and never observed their cases 

 to differ in any respect from those of my other patients. 

 Indeed, the disease is so mild that it seems as if it might 

 at all times be communicated with the most perfect safety." 



I shall here take the oportunity of thanking Dr. Mar- 

 shall and those other gentlemen who have obligingly pre- 

 sented me with the result of their inoculations ; but, as they 

 all agree in the same point as that given in the above 

 communication, namely, the security of the patient from the 

 effects of the smallpox after the cow-pox, their perusal, I pre- 

 sume, would afford us no satisfaction that has not been am- 

 ply given already. Particular occurrences I shall, of course, 

 detail. Some of my correspondents have mentioned the ap- 

 pearance of smallpox-like eruptions at the commencement 

 of their inoculations ; but in these cases the matter was 

 derived from the original stock at the Smallpox Hospital. 



I have myself inoculated a very considerable number 

 from the matter produced by Dr. Marshall's patients, origin- 

 ating in the London cow, without observing pustules of 

 any kind, and have dispersed it among others who have 

 used it with a similar effect. From this source Mr. H. 

 Jenner informs me he has inoculated above an hundred 

 patients without observing eruptions. Whether the na- 

 ture of the virus will undergo any change from being 

 farther removed from its original source in passing suc- 

 cessively from one person to another time alone can de- 

 termine. That which I am now employing has been in 

 use near eight months, and not the least change is per- 

 ceptible in its mode of action either locally or constitu- 

 tionally. There is, therefore, every reason to expect that its 

 effects will remain unaltered and that we shall not be under 

 the necessity of seeking fresh supplies from the cow. 



The following observations were obligingly sent me by 

 Mr. Tierny, Assistant Surgeon to the South Gloucester 

 Regiment of Militia, to whom I am indebted for a former 

 report on this subject: 



" I inoculated with the cow-pox matter from the eleventh 

 to the latter part of April, twenty-five persons, including 





