170 PARASITES OF MAN 



his request I confirmed his opinion that the diseased meat was 

 infested with Trichinae. A few days afterwards I announced 

 the discovery in the pages of the ' British Medical Journal' 

 for April 22, p. 435. It happened, also, that at the time 

 I was delivering a course of lectures before the Society 

 of Arts ; consequently, in my second discourse (which was 

 devoted to the parasites of cattle) I gave full details of the facts 

 that were obtained. Taking a small portion of the flesh which 

 I judged to be affected to an average extent I addressed the 

 audience as follows : 



" If you calculate from one portion only, you might, if 

 you had stumbled upon a part which was more infested with 

 parasites than another, be led to over-estimate the degree 

 of trichinisation. Taking proper precautions I have calcu- 

 lated that one scruple of this trichinous flesh would give us 

 4320 parasites, and two scruples would therefore, yield 8640. 

 Without speaking so precisely to numbers, I do not hesi- 

 tate to aver my belief that there are at least 5000 of these 

 parasites inside this small piece of ham. The number is pro- 

 bably close upon 8640. In one drachm that would give us 12,000, 

 and in an ounce 103,000, according to the old apothecaries' 

 weight. If, however, we calculate according to the ordinary 

 weight used by butchers, we should say that one ounce contains 

 43 7g grains of meat, and therefore the number of parasites in one 

 ounce would be 85,000. Thus, in one ounce of meat from this 

 particular pig you have 85,000 Trichinae, calculated at the rate 

 of 200 in the grain, for I have purposely cut off the odd numbers. 

 You may say, if a person can survive 18, 20, 30, or 40 millions, 

 he would not take much harm from eating a piece of flesh 

 containing only 8640 parasites. Such a portion, however, 

 would be quite sufficient to make any one of us extremely 

 uncomfortable were we to eat it, for supposing its contained 

 parasites to be alive, it might prove dangerous to life. Why ? 

 The explanation is this : Half of those 85,000 parasites, at the 

 very least, will, in forty- eight hours after ingestion, have become 

 fully-developed females ; and from each of these 42,000 there will 

 proceed at least 1000 as a brood, so that the entire progeny 

 (and it is they that do the mischief by their independent 

 migrations through our tissues) will eventually yield about 

 42,000,000 entozoa. If we should be so voracious as to eat a 

 pound of such trichinised flesh, then there would be 400,000,000 

 as the result of a single meal. 



