204 On Vaccination. 



drogen gas) in the common way, with sulphuric acid, 

 water, and iron filings. This result I experienced several 

 times ; the cylinder resting on the copper end of a Galvanic 

 trough consisting of 25 pairs of plates, 2^ inch. When ihe 

 nose was placed on a cylinder connected with the zinc end, 

 no such smell was produced. Quere, How was the inflam- 

 mable air (if any was) produced to make so strong a smell ? 

 The first time I perceived this smell was on Saturday last. 

 I again tried the experiment this evening, and found the 

 same result. I likewise tried it with two troughs, consisting 

 in all of 50 pairs of plates j and then also perceived the 

 smell : but the experiment was from the number of plates 

 so very unpleasant (the shock being great) that I did not 

 continue it very long, and did not determine whether the 

 smell was proportionally strong. 



With these 50 pairs of plates another effect occurred, 

 which I had never seen before. I introduced in the circuit 

 a small glass tube filled with milk instead of water, and 

 whilst it remained in its place I did not sec any alteration 

 take place ; but when I took out the wire, which was a silver 

 one, and had been connected with the zinc end, I found a 

 sort of crust adhering to it which looked like cream. Quere, 

 Was not this curd formed by acid from the zinc end i 

 A gold wire, which was connected with the copper end, I 

 neglected to examine. 

 April 7,1800. yi Friend to Plujsical Inqjiiries. 



XXXVI. On Vacciiiation. An Examination of several of the 

 Mis-statements of Dr, Rowley. By Mr. J. J. Haw- 

 kins, of Islington, 



To Mr. TillocL 



SIR, 



xIavixg for some years seen the inost beneficial effects 

 from the introduction of the cow-pock, as well from the 

 practice of many of my friends, as with several I have my- 

 self vaccinated, I felt it a duty, on the first publication of 

 Dr, Rowley's pamphlet; entitled " Cow-Pox Inoculation np 



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