980 SUMMARY OF CURRENT RESEARCHES RELATING TO 



realized in the starch mass introduced by A. Pansch, and since recom- 

 mended, with various modifications, by Wikszemski, Dalla Eossa, 

 Meyer, and Browning.* 



As starch is insoluble in alcohol and cold water, it becomes hard 

 when injected into the blood-vessels simply by the exudation of the 

 liquid with which it is mixed. (That the starch-grains forming the 

 mass remain entirely unchanged may be easily demonstrated by 

 making a microscopic examination of the contents of an injected 

 vessel.) 



The mass originally recommended by Pansch consisted of wheat- 

 flour and cold water, to v^hich was added a sufficient quantity of the 

 desired colouring matter. Later experiments have shown that pure 

 starch is better than flour. 



Mass for Or dinarij Injections. — Dry starch ("laundry" is good), 

 1 vol. ; 2J per cent, aqueous solution of chloral hydrate, 1 vol. ; 

 95 per cent. alcohol,| 1/4 vol. ; colour, 1/4 vol. Since almost any 

 animal injected may afford some organ worth preserving, it seems 

 better to employ permanent colours for tinging the mass. Among 

 those which are available, probably vermilion, red lead, ultramarine, 

 chrome, orange, yellow or green are preferable. 



Pre]paration of the Colour. — Dry colour, 1 vol. ; glycerin, 1 vol. ; 

 95 per cent, alcohol, 1 vol. To avoid lumps, which would clog the 

 cannulse, or small vessels, the colour is thoroughly ground with the 

 liquid in a mortar. It is stored in a well-stoppered bottle, and is 

 prepared for use simply by shaking. 



Special Mass. — For the injection of brains, and, perhaps, for other 

 rapidly perishing specimens, it seems best, as suggested by Wilder, 

 to use strong preservatives in preparing the mass. Corn starch (that 

 used for food), 1 vol. ; 5 per cent, aqueous solution of chloral hydrate, 

 1/2 vol. ; 95 per cent, alcohol, 3/4 vol. ; colour, 1/4 vol. For con- 

 venience and economy, a considerable quantity of either of the masses 

 described above may be prepared at once, and kept in a wide-mouthed 

 specimen or fruit jar. A smooth stick in each jar is convenient for 

 stirring the mass, which should always be done just before using. The 

 syringe may be filled directly from the jar, and any mass remaining 

 in the syringe after the injection is finished may be returned to 

 the jar. 



If it is desired to have the mass enter very fine vessels, some of 

 the stock mass, as given above, diluted with an equal volume of 

 water or chloral solution, may be injected first, and immediately 

 followed by the undiluted mass, or for large animals, a mass contain- 

 ing twice the usual amount of starch. In whatever form the starch 

 is used, it is necessary to work somewhat expeditiously, because the 



* See A. Pansch, Arch. f. Anat. und Entwickl., 1877, pp. 480-2, and 1881, 

 pp. 76-8; Wikszemski, ibid., 1880, pp. 232-4; Dalla Eossa, ibid., pp. 371-7; 

 H. V. Meyer, ibid., 1882, pp. 60-1, and 1883, pp. 265-6; Browning, 'Annals of 

 Anatomy and Surgery,' 1884, pp. 24-5. 



t The chloral and alcohol prevent fermentation in the mass when it is kept in 

 stock; the alcohol also increases the fluidity and likewise the more rapid 

 hardening in the vessels ; both, of course, act as a preservative upon the animal 

 injected. 



