ROPY WHEY AND THICK MILK. 281 



particular attention to fumigating the stalls out with burning 

 sulphur, scouring the milk vessels with soda solution, &c., in 

 order to eradicate the evil as quickly as possible. 



On the other hand, the Dutch look on the bright side of this 

 evil, and even derive benefit from it, the most palatable production 

 of the Netherlands, viz., Edam cheese, being prepared with the 

 aid of ropy whey (Dutch, Wei). The first observations on and 

 experiments with this ropy whey were made in the " fifties " by 

 a farmer (name unknown) of Assendelft in Holland, but it did 

 not come into general use in the manufacture of Edam cheese 

 until 1887, when Boekel recommended it, most emphatically. 



WEIGMANN (VII.) examined such whey, and found in it large 

 quantities of a fission fungus, which is mostly arranged in pairs, 

 but frequently also in chains, and bears the name of Streptococcus 

 hollandicus. Sterile milk inoculated with this organism becomes 

 ropy and sour in twelve to fifteen hours at 25 C. 



The same coccus was also found by Weigmann in the com- 

 mercial products known as Tcettemcelk or Twtmcelk (thick milk) 

 in Norway, and Filmjolk (stringy milk) in Finland and Sweden. 

 This strongly sour, ropy, thick mass, the casein of which is in the 

 condition of fine flakes, is a highly prized article of nourishment 

 among the Scandinavian races, and is artificially prepared from 

 normal milk by either rubbing the interior of the milk-pails over 

 with butter- wort (Pinguicula vulgar vV), called in Norway Tcette- 

 grces, or by feeding this plant to the milch-cows. The leaves are 

 found to be infested with a fission fungus which turns milk ropy, 

 and is presumably identical with the above-named streptococcus. 

 As already remarked, the occurrence of ropiness in milk is usually 

 accompanied by acidification, whereby the development of nume- 

 rous other species of bacteria is prevented. This accounts for the 

 circumstance that Taetmselk will keep for months without alteration 

 if stored at a low temperature. 



Herz was the first to record observations with regard to so- 

 called soapy milk, a term applied by him to milk that exhibits 

 a taste of soap and lye, and does not curdle, but only deposits a 

 slimy sediment, even after prolonged standing. The cream from 

 this milk froths up very strongly when churned. H. WEIGMANN 

 and G. ZIRN (II.) had occasion, in 1893, to examine a milk of 

 this kind, and they succeeded in isolating therefrom a bacillus 

 which is capable of converting normal milk into the soapy con- 

 dition, and is therefore termed Bacillus lactis saponacei. It was 

 afterwards discovered that the organism originated in the litter, 

 which was in a damaged condition. When that was withdrawn 

 and the cows littered on sound straw, the milk no longer suffered 

 from this complaint. 



