INFECTION BY MEANS OF FOOD. 157 



flesh is tasted by the butcher, cook, or housewife, in order to estimate 

 the proper quantity of salt and pepper. Further, in this state it forms 

 the favourite food of many persons, and even whole classes e.g., the 

 workmen in the manufacturing districts of North Germany. It may 

 also happen that we derive parasites from sausage or ham which has 

 come into contact with infected pieces of flesh or with living worms in 

 the butcher's shop. The bladder- worm of the pig, or its ' head/ is often 

 accidentally introduced in this fashion, especially since the butchers, 

 knowing the law against measly flesh, take the greatest care always 

 to cut away and remove the parasites when they appear on the surface. 

 Where the custom of private slaughtering prevails, as in the middle- 

 class families of North Germany, the parasites may be found in the 

 kitchen or store-room, and thus arise many possibilities of trans- 

 ference and importation. One may, of course, urge that a bladder- 

 worm could hardly be overlooked, or inadvertently swallowed, but 

 the ' head ' is enough for the development of the tape- worm, and 

 being easily separable, could not in this state be distinguished from 

 a little lump of fat without close examination. 



Cooking even boiling and roasting is not a constant or sufficient 

 protection against infection. It has indeed been asserted and observed 

 that living intestinal worms (usually Ligula* but sometimes also the 

 so-called Filaria piscium 2 ) are occasionally found in boiled or baked 

 fish. Experiments were made by Pallas 3 and by Bloch, 4 in order to 

 test the truth of this. The worms were cooked some alone and some 

 within their hosts, which are usually small. The results were, however, 

 only doubtful, but it is impossible any longer to doubt the correctness 

 of the statement. By my experiments in 1860, published in the first 

 edition of this work, I proved that trichinous flesh is by no means 

 thoroughly disinfected by the usual treatment, and as little by salting 

 as by smoking. This statement, which therefore applies to salt pork, 

 smoked sausage, and ham alike, has been corroborated both by obser- 

 vation and experiment, 5 and thoroughly overthrows any faith in the 



1 See a case cited by Rosenstein ("Kinderkrankheiten,'' 3d ed., p. 445, 1774) of such 

 a worm found living in a cooked bream. 



2 Such a case was related to me by my since deceased friend Dr. Kriiger, in Brunswick. 

 A tolerably large cod-fish, which was cooked and brought to table, contained in its flesh 

 many dozen living Filarice. 



3 Neue nord. Beitrdge, Bd. i., p. 98, 1781. 



4 " Abhandl. von der Erzeugung der Eingew. Warmer," p. 3 : Berlin, 1782. 



6 Compare Klichenmeister, Haubner, and Leisering, Bericht uber das Veterindr- 

 wesen Sachsens, p. 188, 1862; Rupprecht, "Die Trichinenkrankheit," p. 112, 1864; 

 Furstenberg, Wochenblatt der Annalen der Landwirthschaft, No. 30, p. 274, 1864; 

 Kiihn, Mittheilungen des landw. Institutes, p. 1-84, Halle, 1865 ; Perroncito, " Sulla 

 tenacita di vita del Cisticerco," Annali Accad. Agricdtur di Torino, vol. xix., 1876, and 

 vol. xx., 1877. 



