WELLMAN S, PEPPER S, AND TELEMANN S METHODS. 11 



WELLMAX's SOD It M ACETATK CEXTRIFl <JE METHOD. 



Wellnian (1910) employs ;i method which a])pears to he a modifica- 

 tion of Bass's (11)09) method, but as it is not clear just what Welhuan 

 means by his statement of his method, the writer has not tested it. 

 His method, which is for hookworm eggs, is given as follows: 



The principle involved was first employed indejiendently by the writer and by 

 Dr. Bass, of New Orleans, Dr. Bass being the tirst. to publish his results. Our 

 own method is to use two solutions of sodium acetate of sjK'cific gravities of 

 1.050 and 1.250. respectively. A portion of suspected feces is mixed with one of 

 these solutions and centrifuged for about 10 seconds, the liquid decanted, then 

 the other solution is poured on and mixed gently, the whole again centrifuged, 

 and this process related until the eggs are all in one layer, the sand and other 

 heavy ingredients of the feces remaining below and the light fioccnlent com- 

 ponents lying above the zone in which the eggs remain. With this technique 

 one slide contains as many ova as 50 or 100 slides by the ordinary method. Dr. 

 Bass uses calcium clilorid for his solutions, but the writer has not been able 

 to employ this salt satisfactorily on account of its hygroscopic properties. 



It is unfortunate that Wellnian does not state just why the hygro- 

 scopic properties of calcium chlorid are objectionable, as Bass em- 

 ploys this salt on account of these properties. 



PEPPER'S ADHESION METHOD. 



An interesting application of technique to a particular case is that 

 of Pepper (1908). He takes advantage of the stickiness which he 

 finds to be a property of human hookworm eggs in the following 

 manner: Washed and sedimented feces are put on a slide for a few 

 minutes and then immersed gently in water; on lifting it out the 

 eggs are found adhering after everything else has been washed away. 

 This process may be repeated and numerous eggs collected. Pepper 

 does not find the same stickiness in the case of Ascarix, TrirJniris, or 

 Tfpnia eggs. 



Stiles (1910) has given the smear method and the methods of Pep- 

 per (1908) and Bass (1909) for the examination of human feces for 

 evidence of hookworm infection. 



TELEMANN'S ETHER HYDROCHLORIC ACID METHOD. 



Another modification of method consists in using chemical as well 

 as physical means to secure a concentration of parasitic material. 

 Telemann (1908). who appears to have been the first to use chemical 

 methods in examining feces for parasite eggs, uses the following 

 technique: Small particles are taken from a number of places in the 

 feces under investigation and shaken up in a mixture 1 of equal parts 

 of ether and pure hydrochloric acid in a reagent glass. ( I believe 

 that T have had slightly better results from adding ether first, stirring 

 well, and then adding the hydrochloric acid.) The ether dissolves 



