368 Dr. W. Henry On the Disinfecting Powers of increased 



lymph was placed, were heated during intervals varying from 

 two to three hours, at a temperature never below 160° nor 

 above 165° Fahrenheit. The trials were judiciouslj' varied 

 by Mr. Gee, by inserting each specimen of the matter which 

 had been dried, into one arm only of a healthy child ; while 

 into the other arm of the same child recent matter was in- 

 serted. In every instance, the heated matter proved ineffi- 

 cient ; while the matter which had been dried at the tempera- 

 ture of the atmosphere produced a satisfactory pustule. 



4. For the sake of obtaining a sufficient number of in- 

 stances, I requested Mr. Marsden, House-Surgeon of the 

 Manchester Royal Infirmary, to make trial of some genuine 

 vaccine lymph which I had received from him, and had then 

 submitted to heat. One specimen had been placed two hours in 

 a steady temperature of 150° ; a second four hours in the same 

 temperature ; a third two hours, and the fourth four hours, 

 in the temperature of 172°. In no one instance, did any of 

 these specimens, when inserted in the usual manner, produce 

 the vaccine pustule. 



5. Descending in the scale of temperature, another portion 

 of vaccine lymph was exposed to an uniform heat of only 

 120° Fahrenheit for three hours. Two children, inoculated 

 by Mr. Gee with this matter, received the infection, and the 

 pustules were, in each case, remarkably well characterized. 

 From their arms matter was taken, with whicli upwards of 

 forty children have been vaccinated, who have gone through 

 the disease in the most satisfactory manner. 



It may be considered, then, as established by the experiments 

 which have been related, — 1st, That vaccine matter is not de- 

 stroyed by a temperature of 120° Fahrenheit; and it is even 

 probable that it would sustain, without losing its efficiency, 

 a heat several degrees higher ; — 2ndly, That vaccine lymph is 

 rendered totally inert by exposure to a temperature of 140° 

 Fahrenheit. May we not hence infer, that those subtile 

 animal poisons which lie dormant in the state of JbtniteSf 

 are likely to be disarmed of their terrors by the same simple 

 means ? The expectation, I am aware, rests entirely on ana- 

 logy; but the analogy appears to me sufficiently strong to 

 render it desirable that it should become the parent of expe- 

 riments. It is with that view onl}' that I propose it to the 

 enlightened physicians of this and other countries, who have 

 the means of verifying or disproving the inference by experi- 

 ments on the more diffiisible and active contagions. Until, 

 indeed, the soundness of the analogy has been established by 

 a sufficient number of facts of the latter class, no extensive 

 practical measures can safely be grounded upon it. 



