320 THE ANIMAL PARASITES OF MAN 



customs cannot be altered in a short time. As the usual process of 

 pickling and smoking, even when long continued, does not certainly 

 ensure the death of the trichinellae contained in the meat, and also 

 because in roasting and boiling large pieces of pork a considerable time is 

 necessary to permit the temperature required to kill off the parasites 

 (62-70 C.) to penetrate to the middle of the joint, it appeared to be 

 most practical to have all pigs microscopically examined for trichinellae 

 before they, or parts of them, were placed on the market, and all infected 

 meat condemned, no matter whether the trichinellae were present in large 

 or small numbers, still undeveloped or calcined. Since 1877 obligatory 

 examination of pork has been introduced in Prussia, though as yet it is 

 not thoroughly carried out ; other states of North Germany as well as 

 the larger towns of South Germany soon followed ; a complete army of 

 trichina inspectors, officially examined and periodically controlled by experts, 

 and whose number in Prussia amounted to 27,602 in 1896, and was even 

 increased to 28,224 in 1899, have the charge of examining pork on certain 

 lines laid down. The orders, however, are by no means narrow. The 

 proceeding is usually that the trichina inspector himself goes to the 

 slaughter-houses, or special samplers take pieces of the muscles that are 

 known to be the favourite seats of the parasite (strips of the diaphragm, 

 the rib part of the diaphragm, muscles of the tongue and larynx, inter- 

 costal and abdominal muscles) ; six small portions are separated from each 

 piece, pressed between slides or special compressors, and carefully gone 

 through by examining them with a microscope at low power. The pigs, free 

 from trichinellae are passed for commerce ; trichinous pigs, on the other 

 hand, in Prussia, are only allowed to be used for industrial purposes, i.e., 

 the hide and bristles are used, the fat is allowed to be melted down, or 

 certain parts are used for the manufacture of soap or glue. In Saxony, 

 however, it is still permitted to place trichinous flesh on the market, fully 

 declaring its nature, and after having been heated to its deepest strata at 

 a temperature of 100 C. in a suitable apparatus, and under the supervision 

 of a veterinary surgeon. 



As TO THE PROPORTION OF TRICHINOUS PIGS to healthy ones, the follow- 

 ing tables give the figures for Prussia. 



The proportion, however, is not only subject to variation in separate 

 years, but differs according to the district ; thus, in 1884, in the State 

 district of Minden there was one trichinous pig to 30,146 healthy animals, 

 in Erfurt i : 14,563, in the district of Gnesen i : 101, in Schrimm i : 86, 

 and in Schroda i : 68. 



In Germany trichinella is becoming LESS COMMON in pigs (Ostertag). 



(a) Prussia- 

 Pigs found 



Year. to be Trichinous. 



1878 1885 .. .. .. .. .. 0-061 0-048 percent. 



1886 1892 .. .. .. .. .. 0*033 0-043 



1896 .. .. .. .. .. .. 0-021 



1899 .. .. .. .. .. .. 0*014 



