EXAMINATION AND PRESERVATION MEDIA. 237 



According to LOCKK (Boston. Med. Surg. Journ., 1890, 

 p. 514) there should be added to salt solution (which to be 

 isotonic should contain, according to HAMBURGER, 0'9 to 1 

 per cent, of salt) O'Ol per cent, chloride of potassium, and 

 0*02 per cent, chloride of calcium, in order to obtain an 

 " indifferent " liquid. 



MALASSEZ (C. R. Soc. Biol, iii, 1896, pp. 504 and 511) 

 takes for erythrocytes about 1 per cent, sodium chloride. 



DEKHUYSEN (Onderz. Phys. Lab. Leiden., 1900, p. 149) 

 takes for blood of Rana 0*8 per cent. 



For Selachians, MUSKENS (Tijd. Nederb. Dierk. Ver., 1894, 

 p. 314) finds 2J per cent, right; and RODIN (Com^tes Rend., 

 1900, p. 1009) 1'5 to 2*6 per cent., according to the species. 



ENGELMANN (Deiitsch. metl. Wochenschr., xxix, 1903, p. 64), 

 finds that 0'9 per cent, is isotonic with human blood-serum, 

 and 0'64 per cent, for red blood corpuscles of the frog. 



KRONECKER'S " Artificial Serum" (from YOGT et YUNG 

 Traitv. d'Anat. Comp. Prat., p. 473) consists of common salt 

 6 parts, caustic soda 0'06, distilled water 1000. 



BOHM und OPPEL (Taschenbuch, 3 Aufl., p. 19) take car- 

 bonate of soda instead of caustic soda. 



403. PICTET'S Liquid (Mitth. Zool. Stat. Neapel, x, 1891, 

 p. 89). 5 to 10 per cent, solution of chloride of manganese. 

 These proportions are for marine animals, and for terrestrial 

 animals will generally be found much too high. For these 

 from 1 per cent, to 3 per cent, will be nearer the mark. I 

 find this liquid excellent. 



404. Aqueous Humour, Simple White of Egg. Require no 

 preparation beyond filtering. They may be iodised if desired 

 (see next ), or mixed with salt' solution. 



405. Iodised Serum. MAX SCHULTZE (Virchow's Archiv, 

 xxx, 1864, p. 263). I take the following from RANVIER 

 (Traite, p. 76). 



The only serum that gives really good results is the amniotic 

 liquid of mammals. Flakes of iodine are added to it, and the 

 fbisk frequently agitated for some days. The flask should 

 have a wide bottom, so that the serum may form only a 

 shallow layer in it. 



