1899] MICROSCOPICAL JOURNAL. 349 



BIOLOGICAL NOTES. 



Iv. H. PAMMEL. 



History of a Tuberculous Herd. — Dr. H. L. Russell 

 (Bull. 78 : Wisconsin Agricultural Experiment Station) 

 gives some interesting facts concerning the history of a 

 herd of tuberculous cows which was under his observation 

 for several years. Calves from tuberculous' mothers as 

 well as progeny from non-reacting animals have been al- 

 lowed tosuckle several of thereactinganimals ; also healthy 

 young cattle have been in contact with the affected herd in 

 a stable and pasture to see if they would acquire the dis- 

 ease by ingestion or inhalation. In no case was the dis- 

 ease contracted. Frequent microscopic examinations were 

 made of the milk and in not a single case could tubercle 

 bacilli be found. The bacilli were always found in milk 

 where small quantities of tuberculose sputum had been 

 added to the milk. Milk from the animal is not a frequent 

 source of danger, though from a precautionary stand-point 

 to public health it should be pasteurized. 



Bacterial Treatment of Sewage. — Pidgeon (Jour. Royal 

 Agricultural Society, III. 10 : 249) discusses the bacterial 

 treatment of sewage as it is now carried on in some of the 

 cities of England. At Exeter where a septic system of 

 sewage purification has been adopted for the treatment of 

 sewage derived fpom St. Leonards, a suberb having a pop- 

 ulation of 1,500 people and a flow of sewage averaging 54,- 

 000 gallons per 24 hours, good results have been obtain- 

 ed. During the first year's experience at Exeter the scum 

 on the septic tank varied in thickness from four inches in 

 the winter to one inch in summer. The effluent from the 

 septic tank was suitable for land treatment. It is stated 

 that no sludge is produced from such substances as paper, 

 rags,or even feathers as they disappear in the septic cham- 

 ber. The nitrifying filter occupies a space of 400 square 

 yards while the septic chamber has an area of 130 square 

 yards. This makes a total of nearly one-ninth of an acre. 

 Without the use of chemicals the excreta of 1,500 people 



