252 IXFLAMMATIOX 



important factors in pathology; the products of tissue disintegration 

 have simihir effects.'' Certain drugs (notably quinine, morphine 

 and chloral) when injected subcutaneously seem to reduce the amount 

 of leucocj'tic emigration at a point of local injury (Ikeda).'^ In 

 gas gangrene negative chemotaxis is striking, possibly depending on 

 the abundant organic acids produced by gas bacilli.'" 



V. Sicherer-° found that chemotaxis of leucocytes may be observed 

 outside the body. If a tube containing positively chemotactic sub- 

 stances (dead beer-j^east cells and dead staphylococci were the strong- 

 est) is placed with one end in a leucocyte-containing exudate, the 

 leucocytes pass up into it against gravity. 



Bloch^^ demonstrated that carbol-gh'cerol extracts made from 

 each of the different viscera and tissues exerted a positive chemotaxis, 

 discrediting the statements of Goldscheider and Jacob that only 

 extracts of hematogenetic tissues showed positive chemotaxis. Egg- 

 albumen, gelatine, albumen-peptone, and alkali albuminate w'ere also 

 positive, carbohydrates feebly so, and fat not at all. Metallic copper, 

 iron, mercury, and their salts have also been found to be chemotactic 

 substances, but it is very probable that thej- act in part through 

 destrojang the tissues in their vicinity, which give rise to decom- 

 position-products having a positive effect. Adler,'-- however, found 

 that bichloride of mercury as dilute as 1 : 3000 caused more leucocytic 

 invasion of a piece of saturated elder pith than did even cultures of 

 pyogenic bacteria. ^^ 



Aletchnikoff observed that leucocytes might, after a time, be at- 

 tracted toward substances that at first seemed to repel them. If the 

 blood is full of toxins, the subcutaneous introduction of bacteria does 

 not lead to a local accumulation of leucocytes, presumably because the 

 difference in chemotaxis between the blood and the tissue fluids is not 

 great enough to cause emigration; in this connection should be men- 

 tioned Pfeffer's observation that B. tcrmo in a peptone solution will 

 not migrate toward another stronger peptone solution, unless the lat- 

 ter is at least five times as strong as the former. Leucocytes will 

 migrate freely toward substances that kill them; of the bacterial prod- 

 ucts the toxins of pyocyaneus and diphtheiia l)acilli l)eing especially 

 destructive and causing typical karj'orriiexis.^^ Substances soluble 

 in lipoids are said by Hamburger-' to increase phagocytic activity 

 when in extreme dilutions, although stronger concentrations are highl}- 



" See Dold, Arb. Path. Inst. Tiihingoii, 1014 («»). .SO. 

 '».Iour. Phamuicol., 1916 (8), 1.37. 



'■'Sec Kinivs-Kohcits ;iiul CowoU, .lour. Putli. I^act.. 1!)17 fJl i. 473. 

 =» VAiwi. f. iiakt., 1,S99 (2()), 3()0. 

 -' Cent. f. allK. Path., 1K9() (7), 785. 

 -- Festschr. for -V. Jacolii. 1900, New "\ oik. 



-•H'onccrnin^ the ctTects of iotlin and iodide.s upon the ItMic.ocvtos. see TIeiiiz, 

 Vircliow's Aicli., 1S99 (l.W), 44. 



2* Schiirniann, Cent. f. Pathol., 1910 (21), 337. 



"Arch. NY>erland., 1912 (III, H), 134; Brit. M<<.|. ,luur.. 191(1 a\ 37. 



