376 EXPERIMENT STATION EECOED. [Vol. 87 



gests that tissue disintegration with absorption of toxic products Is responsible 

 for the changes noted, and that bacterial invasion is important only in so far 

 as it gives rise to toxic substances. The most marked increase in globulin 

 content of the blood serum was found in animals which showed some of the 

 complications met with in loop animals, as rupture of the loop and peritonitis. 

 The globulin increase was especially rapid and large in the latter condition. 

 This reaction is deemed to be of diagnostic value in acute infections. 



The expermental data are submitted in tabular and graphical form and 

 discussed. 



The mechanism of the agglutination reaction, H. Peiestlky (Jour. Eyg. 

 [Cambridge^, 15 (1917), No. 4, pp. 485-504) .—From the study reported the 

 author concludes that the agglutination and precipitin reactions are probably 

 essentially the same in nature. " The agglutination of bacteria by specific sera 

 is probably due to the formation of altered serum protein in and around the 

 bacteria and the subsequent flocculation by electrolytes of this altered protein 

 and the bacteria. This altered protein Is probably altered serum globulin, and 

 possibly other altered serum proteins." 



The inhibition phenomenon exhibited on heating an agglutinating serum was 

 found to resemble closely the inhibition by acids and alkalis. The inactivation 

 of an agglutinating serum by heating and the production of " zones of inactiva- 

 tion " are deemed probably due to the formation of inhibitory substances rather 

 than to the destruction of the agglutinin. 



The data are reported in detail and discussed. 



On factors limiting the extent of the concentration of antitoxic sera by 

 the fractional precipitation methods at present employed, Annie Houeb 

 (Jour. Ilyg. [Cambridge], 15 (1917), No. 4, pp. 580^90).— Detailed tabular ex- 

 perimental data submitted show that a product containing not more than 20 

 per cent of protein and having a potency eight or ten times that of the original 

 eerum can be obtained where the pooled antidiphtheritic sera have a unitage 

 not greater than 500 and where the heat denaturatlon is about 40 per cent. 



It is noted that with the methods at present employed for the concentration 

 of an antitoxic serum for therapeutic use., a concentration of more than 22,500 

 units of antitoxin per gram of protein can not be obtained. 



See also previous notes (E. S. R., 35. p. 6S0; 36. p. 178). 



The effects of senim treated with pararabin, E. Zunz and C. MoHiUEvaTH 

 (Jour. Expt. Med., 25 (1917), No. 2, pp. 211-229).— Uorse serum treated with 

 pararabin (a portion of the carbohydrate of agar practically free from nitro- 

 gen), as previously noted by Zunz and Grelat (E. S. R., 36, p. 575), produced the 

 same results as when treated with agar. 



A preliminary report on two new methods of preventing blackleg by 

 means of an antiblackleg serum and an aggressin, F. S. Schoenlebeb, T. P. 

 Haslam, and O. M. Franklin (Kansas Sta. Circ. 59 (1917), pp. 7). — The 

 authors describe the preparation of a highly potent antiblackleg serum from 

 the horse. The serum was found to be curative for calves in the early stages 

 of the disease. The passive immunity produced, however, is of short duration, 

 and in order to produce an active Immunity of a certain degree virus pellets 

 are administered a few days after the serum treatment. 



The edematous fluid sterilized by filtration through a Berkefeld N filter in 

 doses of from 8 to 15 cc. possessed a strong immunizing power and was found 

 suflicient to protect calves against doses lethal for nonvacciuated animals. 



The vaccine has been found to yield excellent results in field treatment in 

 doses of 5 cc, producing in calves six months of age or older suflicient im- 

 munity to protect them for the remainder of their susceptible period. 



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