Production of Antisera 61 



boxes, containing wool at the bottom, and suitably labelled. The object 

 in placing the tubes vertically and not horizontally, is to ensure tin- 

 gravitation of any suspended matter into the lower drawn-out end, 

 where it accumulates, and can be readily disposed of by cutting the 

 tube above the layer of deposit, by means of a diamond, when about to 

 use the serum for testing. (Regarding the use of preservatives see 

 p. 64.) 



The Choice of Animals for Immunization. 



Rabbits appear to be the most suitable animals for the production 

 of antisera. 32 kinds have been produced by me through injecting 

 rabbits with inammalian (non-rodent), avian, reptilian, amphibian, and 

 crustacean bloods. Most observers have used the rabbit in their 

 work, doubtless because of the greater convenience and moderate 

 expense, the guinea-pig not being so suitable, for the reason that 

 it yields less antiserum. Guinea-pigs have been used by but a few 

 observers, including myself. The rabbit is therefore to be selected, 

 apparently in all cases where antisera are required for bloods other than 

 those of rodents. We have sufficient evidence to show that precipitins 

 are not formed in the serum of closely related animals. Thus Bordet 

 and Hamburger obtained no precipitins for rabbit blood by treating 

 guinea-pigs with rabbit serum, and all that Gengou could claim was 

 that the serum of such guinea-pigs produced a slight opalescence in 

 rabbit blood dilutions, never a precipitum. Nolf was unable to produce 

 antisera in pigeons treated with fowl serum, the reason being apparent 

 from my extensive investigation of avian bloods, which, throughout, 

 have been found to react to antifowl and antiostrich sera. In other 

 words, birds appear to be too closely allied for the purpose of inter- 

 avian antiserum-production. 



In Tchistovitch's classical experiments precipitins for eel serum 

 were obtained by treating goats, dogs, rabbits and guinea-pigs. Anti- 

 rodent serum (for rabbit) has been produced by Nolf by injecting rabbit 

 blood into the fowl. Hamburger (6, xi. 02, p. 1190) was unable to 

 obtain antiserum for egg-white from a dog treated therewith. Corin 

 has on the other hand used the dog for the production of antisera, 

 according to Strubc (1902). Uhlenhuth (18, ix. 02, p. 680) has not 

 had encouraging results with other animals than rabbits. For instance, 

 he treated a lamb and a goat with human blood and ascitic fluid during 

 2 months, injecting respectively a total of 1'5 and 2 litres thereof into 

 the animals ; the antiserum was too weak for practical use. De Lisle 



