EXPERIMENTS UPON THE LIVING ANIMAL. 137 



employed in the case of Koch's comma bacilli by Nicati and Rietsch. 

 In such cases antiseptic precautions must be rigidlj' followed, and 

 use made of iodoform and other antiseptic dressings. The disinfec- 

 tion of the skin of the animal, of the instruments employed, and of 

 the hands of the operator, are details essential to secure success. 



To inoculate tubercular matter, sputum may be rubbed up with 

 distilled water, and some of the mixture injected into a tracheal 

 fistula ; or the first steps of the operation of iridectomy may be 

 performed and tubercular material inserted into the anterior chamber 

 of the eye, but this method is only justifiable when it is absolutely 

 necessary for the results and changes to be observed from day 

 to day. 



To inoculate rabbits or other animals with the virus of rabies, 

 the skull is trephined, and an emulsion prepared from the spinal cord 

 of a rabid animal is injected beneath the dura mater. 



Before every inoculation the instruments must be sterilised in a 

 hot-air sterUiser or by immersion in boiling water in a flat dish or 

 enamel tray heated by a spirit-lamp, and after each operation all 

 instruments should be placed in carbolic acid (1 in 20) or in boiling 

 water, wiped dry, and again sterilised in the hot-air sterihser, before 

 they are put awaJ^ If these precautions are not observed, instances 

 of accidental infection are sure to occur. 



After the inoculation is completed a careful record must be made 

 of the date and details of the experiment. The form in which the 

 virus was used, the quantity employed, and the seat of inoculation, 

 must be taken into account. The animals must be kept under close 

 observation, the temperature taken, and any signs of illness, such as 

 ceasing to feed, difiiculty in breathing, staring coat, and any local 

 signs, such as the development of a tumour or an enlargement of the 

 lymphatic glands, must be carefully noted. 



It is perhaps hardly necessary to add that in this country no 

 experiments of any kind may be performed on living animals without 

 a license. 



Method of Dissection and Examination. 



All animals that die after an experimental inoculation should 

 be examined immediately after death. Every precaution must be 

 taken iu conducting the dissection, to exclude extraneous micro- 

 organisms, and all instruments employed must have been steriUsed 

 in the hot-air steriliser, or by immersion in boiling water. If a mouse, 

 for example, has died after inoculation with anthrax, it should be at 



