288 EXPERIMENT STATION RECORD. [Vol. 40 



glacial acetic acid, and the ensuing precipitate is filtered, pressed, and dialyzed 

 in the usual manner. 



Further observations on the properties of antitoxic sera, Annie Homer 

 (Jour. Physiol, 52 (1918), No. 4, pp. XXXVII, XXX Till). —Certain factors 

 influencing the concentration of antitoxic sera by methods involving the frac- 

 tional precipitation of the heat-denatured sera by ammonium sulphate and by 

 sodium chlorid are discussed. 



On the concentration of antitoxic sera by the salting out of the heat- 

 denatured serum proteins with sodium chlorid, Annie Homek (Biochan. 

 Jour., 12 (1018), Xo. S, pp. 190-209). — This paper reports a study of the possi- 

 bility of shortening the process of concentration of antitoxic sera by treating 

 the heated sera directly with sodium chlorid, together with a further study of 

 the factors inlluencing the heat denaturation of the serum proteins and of the 

 extent to which the denaturation can be carried without rendering the protein 

 antitoxin complex insoluble in brine. The results of the study are summarized 

 as follows : 



The concentration of antitoxic sera can be successfully conducted by a regu- 

 lation of the heat denaturation of the serum proteins, followed by a direct 

 treatment of the heated sera with brine and salt. The end products thus formed 

 are clear and more readily filterable than those resulting from methods In- 

 volving the use of ammonium sulphate. 



With lieal denaturation of the order of from o<» to 40 per cent, the method 

 led to the removal of about 50 per cent of the serum proteins. The potency of 

 the end products was about five times that of the original serum. The degree 

 of concentration was not improved by a further increase in the extent of the 

 heat denaturation, nor by the addition of substances such as cresylic acid or 

 sulphates to the serum previous to its being heated. Under some conditions the 

 heat-denatured proteins precipitated during the heating of sera containing 

 cresylic acid or of which the reaction is more acid than pH=5 do not redissolve 

 in brine, even on long standing. There is, however, evidence that the proteins 

 precipitated during the heating of sera containing electrolytes can be redis- 

 solved by the prolonged treatment of the precipitates with a large volume of 

 brine. For the successful concentration of sera, the precipitation of those pro- 

 teins to which the antitoxin is attached must not be changed from a reversible 

 to a nonreversible type <>f action. 



The method discussed has not furnished end products showing so great a 

 percentage removal of the serum proteins nor a degree of concentration so 

 high as that obtained by the author with the Banzhaf and the Homer methods 

 (E. S. R., 39, p. 487), but is suggested as a practicable alternative method. 



The absorption or saturation test of Castellani: Its applications in sero- 

 diagnosis, and in the recognition of bacterial species, F. E. Taylor (Jour. 

 Uyg. [Cambridge], 11 (1918), Xo. 4. pp. 4L'>-.' t 38).— This is an account of the 

 absorption or saturation test of Castellani. previously noted (E. S. R., 14, p. 

 393), with a general review of its use by different investigators in the study 

 of infections of the typhoid-paratyphoid group, dysentery, the meningococcal 

 group, tetanus, and plague. The technique employed in the application of the 

 test to the serodlagnosis of mixed infections and to the differentiation of closely 

 allied species and types of bacteria is described. 



A preliminary report on the intrapalpebral mallein test, L. Prick (Jmir. 

 Amer. Vet, Med. Amoc., SS [1918), Xo. 5. pp. 597-606. figs. 4).— This is a discus- 

 sion of the Intradermo-palpebral test for glanders as observed in the examina- 

 tion of over 500 healthy and 27 glandered horses. 



The author concludes that the intradermo-palpebral test "Is comparatively 

 a simple, accurate, convenient, and reliable method for detecting glanders in 



