1821.] Dr. Front's Reply to Dr, Yelloly. ^ 



mean which, in the present improved state of surgery shall tole- 

 rably well serve for the whole kingdom. The data we possess 

 are obviously too imperfect to admit of this being done with 

 much precision, and the ratio actually deducible from them (viz* 

 1 in about 6^) seems, when all the circumstances are duly con- 

 sidered, to exceed the truth. On the other hand, the ratio 

 deducible on general principles from the same data, though 

 of course not necessarily more correct than the actual one, hap- 

 pens to coincide more nearly with my views ; hence (and as I 

 am also reasoning generally), I give it the preference.* 



The circumstance which, renders the data in question particu- 

 larly defective is their not including the metropohs, where, 

 according to Mr. Smith's estimate, two-fifths of the whole num- 

 ber of operations in the kingdom are performed. We have no 

 means of obtaining correct information on this point, which is 

 much to be regretted, but when we take into account the 

 acknowledged skill of our surgeons, and the fact that nearly 

 one-half of the above proportion of cases are private, in which 

 of course every circumstance that united extraordinary skill and 

 attention can devise to ensure success is attended to, we cannot 

 hesitate, I think, to draw the conclusion, that the rate of morta- 

 lity is as favourable, if not more so, in London, as in any part 

 of the country. This circumstance, if admitted, will tend to 

 diminish considerably the general ratio of mortality ; perhaps, 

 reduce it to 1 in 7, or upwards, even according to the usual 

 mode of estimation by taking the average of a number of past 

 years. But this mode of estimation is not exactly applicable to 

 my purpose. I wish to represent the rate of mortahty as it exists 

 at this time, when I am willing to believe the surgical art is more 

 perfect than at any former period : this, if admitted, will allow 

 a still further reduction in the rate of mortahty ; so that upon the 

 whole, I trust the ratio given does not much exceed the truth ; 

 and if it does, I acknowledge that I feel much less regret in fall- 

 ing into an error on this side of the question than the other.'!' 



Such are the principal reasons which induce me to prefer the 

 general ratio I have given to that actually resulting from my 

 imperfect data. I do not mean to assert that they are absolutely 

 conclusive, but, on the contrary, willingly admit that there is 

 foom for diversity of opinion on the subject. Every one, there- 

 fore, must decide for himself. 



* Means .f generally speaking, are correct in proportion to the number of observa- 

 tions. Thus, from the multiplied observations of the Bristol data, the mean deduced 

 on general principles differs very little from the actual mean, though both are evidently 

 very far below the general mean as applicable to the whole kingdom. On the other 

 hand, the mean, as deduced in general principles from the Norfolk data, happens to 

 considerably exceed the actual mean, the periods of observation being only two (viz. 

 before and after puberty). This error m excess, however, though of a different kind, 

 serves, in the final generalization, to counteract the error of deficiency in the Bristol data. 



•f- Dr. Marcet estimates the mortality in Guy's Hospital at about 1 in 7. Mr. Mar- 

 tineau, of Norwich, has, I understand, during the last 17 years, performed the operation 

 85 times with the loss of only two patients. 



