652 



SCIENCE 



[N. S. Vol. XXVII. No. 695 



does not depend on the ingestion of im- 

 mune milk. 



Immune defibrinated blood in doses of 

 0.1 CO. to 0.3 c.e. protects against twenty 

 to forty times the minimum pathogenic 

 dose of infected blood, the two being mixed 

 before injection. One cubic centimeter of 

 immune blood given subcutaneously pro- 

 tects against 20 to 40 minimum pathogenic 

 doses of virus given subcutaneously 10 to 

 15 days later. This passive immunity may 

 have a longer duration, since its limits have 

 not yet been determined accurately. 



The immune blood has little curative 

 power when spotted fever is well estab- 

 lished, but when given early and in suffi- 

 cient quantity will shorten the course of 

 the fever by three or four days. 



Vaccination of guinea-pigs may be ac- 

 complished by a single injection or by two 

 or more injections of immune blood mixed 

 with virus in appropriate quantities, with 

 the result that two months later they resist 

 infection by twenty to forty pathogenic 

 doses of the virus. The immunity of vac- 

 cinated guinea-pigs finds expression in the 

 strong protective power of their blood when 

 the latter, mixed with virus, is injected into 

 normal guinea-pigs. 



The results indicate that immune serum 

 may be effective in preventing spotted fever 

 in man, provided that it is given withia a 

 reasonable time following the bite of an 

 infected tick. 



It is also hoped that the vaccination 

 method'will be suiSciently satisfactory and 

 safe to warrant its use in preventing spot- 

 ted fever in man. Its value is yet to be 

 proved on the monkey. 



The nature of the anti-bodies has not 

 been definitely established. 



Artificial Immunity to Glucosides: "Will- 

 iam W. Ford. 

 In considering the subject of artificial 



immunity to glucosides, as compared with 



the immunity produced by the injection of 

 poisonous proteids it should be emphasized 

 that bacteriologists employ the term poison- 

 ous proteids, in a rather indefinite way, 

 hardly ever approved of by the physio- 

 logical chemists. The designation poison- 

 ous or toxic proteids or toxalbumins is thus 

 applied to a group of substances embracing 

 the true toxins characterized by certain 

 definite physiological reactions, but never 

 yet isolated chemically, or obtained in any 

 condition at all resembling chemical purity. 

 These substances are highly poisonous to 

 animals, produce well-marked lesions pecu- 

 liar to each poison injected, act upon the 

 animal body or show their effects upon 

 this body only after a considerable period 

 of incubation; and by the introduction of 

 sub-lethal doses give rise to the production 

 of substances in susceptible animals, which 

 neutralize their poisonous action. They 

 are always closely associated with proteids, 

 and are precipitated by all the well-known 

 proteid reagents, such as alcohol, uranium 

 acetate, aluminium sulphate, ammonium 

 sulphate and a number of others. 



They have not thus far been separated 

 from the proteids with which they are asso- 

 ciated, and since the purest products 

 hitherto obtained still give the biuret re- 

 action and still contain nitrogen and sul- 

 phur it is concluded that these substances 

 must be proteid or proteid derivatives. A 

 more popular designation, proteid-like, or 

 Eiweiss-ahnlich, while possibly less ob- 

 jectionable from the chemical point of 

 view, does not obviate the difficulty result- 

 ing from the use of these chemical terms, 

 since it is rather hard to say just what con- 

 stitutes the difference between a ti;ue pro- 

 teid and a proteid-like body. Although 

 one or two authorities, notably Oppen- 

 heimer,^ believe that the toxins are not pro- 



^ Oppenheimer, " Die Bakteriengifte," in Kolle 

 und Wassermann's " Handbueh der pathogenen 

 Mikroorganismen," Erster Band, s, 344. 



