154 Vaccination. 



disease, reckoning from the time when tlie smali-pox dis- 

 appeared at the end of 1806, to the end of 1809, when it 

 again ceased. The annual births in Norwich for the last 

 four years are about nine hundred ; somewhat less than 

 half of this number, or four hundred, probably belong to 

 the lowest or unvaccinatinc; class; which in three years will 

 produce by births about the number of individuals who had 

 the disease at this period, and which, as I before observed, 

 must have been somewhat more than twelve hundred *. 



*' The moral reflections which necessariiv arise from this 

 melancholy detail need not now be insisted upon. I will 

 however just observe, that had this patient been fortunatelv 

 sent to the Infirmary at the time Mr. fiobinson called upon 

 me, and which was, f believe, before the disease had readied 

 that stage which renders ii infectious, she would not have 

 been in a situation to have coninumicaied it; and the citv, 

 in that instance at least, would liave been spared the dread- 

 ful visitation to which so many human lives were sacri- 

 ficed; and had (he former wise regulations of this court 

 remained in force, it is sufficiently clear that she would 

 have been sent thither." 



To Mr. rUhch. 



Sir, — In plate xvii. of the 3d vol. of Mr. Parkinson's 

 valuable *' Organic Remains," is figured at iig. 'J. the im- 

 pression of an insect, whose s])ecies the author professes 

 himself unable to determine. He will probably therefore 

 not be sorry to be informed through your medium, that it 

 is clearly the impression of the larva of a species of Li- 

 bellula or Dragon Fly ; I conjecture, of L. qundrimaculata, 

 a figure of which may be seen in the filh vol. of Remains, 

 tab.xx.wi. fig. 1. and ^2. What Mr. Parkinson terms " the 

 sting," IS the inttrmcdiare one of the three pointed pro- 

 cesses found at the anus of many of the tribe, but not at 

 all analogous to a sting. The legs have not been, as Mr. P. 

 supposes, eight, but six, the usual number in insects. 

 Jan. a?, 181:^. I Jui, Sir, 8cc. &:c. 



C. E. 



* Admitting this coiijcctiire to be well founded, as more than two years 

 liave elapsed since the smali-pox was in Norwich, it follows, that at this time 

 there are more than eight hundred rhildrrn liablo to catch the disease, 

 should it again find its way into the cilv. If also it he tiue, that this disease 

 is fatal to a sixth of tlie individuals infected, it is equally clear, that unless 

 some etHcient means are adopted to secure the lower classes from the infec- 

 tion, an average annual loss to ouf population of more than sixty persons 

 will be sustained. 



To 



