140 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



porous earths have marked powers of adsorption, some tests were 

 made to determine M'hether such fdtration is attended with loss of 

 theraiH'Utically valuable su])stances. When one sample of tetanus 

 serum, one of tetanus plasma, and one of tetanus antitoxin were fil- 

 tered through kieselfjhur and a Berkefeld type filter, chemical tests 

 showed the adsorption of ])rotein in amounts ranfring from 7 to 35 

 ])er cent of the total. Guinea-pi*r inoculation tests on these same 

 ])roducts showed no measurable loss of antitoxic units in the serum 

 and plasma, but in the antitoxin the loss in potency ranged from 8 

 to 14 ])er cent of the total number of units. Similar experiments are 

 in proo:ress with diphtheria serum, plasma, and antitoxin. The ex- 

 treme conservatism of certain manufacturers' statements of potency 

 leads to the view that in many cases the potency of a product is not 

 'knoAvn, even approximately. A sample stated to contain " about 200 " 

 units of tetanus antitoxin was found to contain 500 per cubic 

 centimeter. 



Serolofj^ical studies with several of the more important spore- 

 bearinp: anaerobic microori^anisms has shown that o;erm-free filtrates 

 of these or<>:anisms will act as antigens in the complement-fixation 

 test, in which an exceptionally wide range between the antigenic and 

 anticomplementary units is obtainable. Promising results have so 

 far been obtained in the identification and differentiation of the fil- 

 trates of these anaerobes. A paper reporting this work was con- 

 tributed to the Journal of Agricultural Research (vol. 19, p. 513). 

 Practical application of this phenomenon has been made in the deter- 

 mination of purity and specificity of the blackleg filtrates intended 

 for immunizing purposes. Further work is being done with the fil- 

 trates of certain organisms. 



EXPERIMENTAL STUDY OF ECHINACEA THERAPY. 



In view of the wide use of echinacea in human and veterinary prac- 

 tice and the claims made regarding its efRcacy in infectious and allied 

 diseases, some laboratory experiments were carried out with various 

 preparations of the plant. " Specific medicine echinacea," " fluid- 

 extract echinacea," and " subculoyd inula and echinacea " were tested 

 on guinea pigs for the prevention or treatment of tetanus, botulism, 

 septicemia, anthrax, tuberculosis, trypanosomiasis, and poisoning by 

 rattlesnake venin. In no case did it show any therapeutic or curative 

 effect. A paper reporting these experiments was prepared for the 

 Journal of Agricultural Research. 



DISEASES OF POULTRY. 



Quail disease was studied, and a form of protozoan organism 

 known as a coccidium was found to cause it. As coccidiosis is success- 

 fully treated in fowls, the same method of treatment may be applied 

 to quail disease. The results of the investigation were published. 



Several outbreaks of rose-chafer poisoning were diagnosed in car- 

 casses of young chickens submitted to the laboratory. Extensive 

 losses among chickens, generally attributed to other causes, result 

 from eating rose chafers which invade certain sections of the country 

 during the latter part of May, June, and early in July. A paper re- 



