548 Proceedings Columbia Biochemical Association [July 



One part of tendon mucoid mixed with one hundred parts of 

 Collagen or edestin can easily be detected by this differential stain- 

 ing process. 



The technique, practical Utility, and applications of the test are 

 now under investigation. 



93. Two new histons. Walter H. Eddy. Tom-cod histon. 

 Tom-cod milt contains a histon which, like thymus histon, is pre- 

 cipitable in two forms: (a) an ammonia-precipitated product which 

 is partially soluble in water, and (&) a sodium-chlorid precipitated 

 product which is readily soluble in water. Both forms give char- 

 acteristic histon tests. Shad histon. Shad milt contains a histon 

 which may be precipitated in two forms: (a) an ammonia-pre- 

 cipitated product which is insoluble in water, and {h) a complex 

 precipitable by Saturation with sodium chlorid, which appears to 

 be a combination of histon and a non-histon protein fraction. The 

 products were prepared by the method already described.^ 



94. Histon nucleoprotein : A protein salt. Walter H. Eddy. 

 Continuing the work on histon-nucleoprotein that has already been 

 described,^*^ and proceeding with the aid of the improved method 

 recently outlined,^^ a neutral water-sol. of thymus histon (which 

 had been precipitated by Saturation with sodium chlorid) was added 

 to a neutral Solution of sodium nucleoprotein from yeast until pre- 

 cipitation was complete. This precipitate was insoluble in water but 

 soluble in 0.05 per cent. sodium carbonate sol. and could be repre- 

 cipitated, without decomposition, by o.i per cent. hydrochloric acid 

 sol. The 0.05 per cent. sodium carbonate sol. was precipitable by 

 conc. nitric acid sol., by very dil. hydrochloric acid sol., by picric 

 acid, alcohol, mercuric chlorid and neutral lead acetate but was not 

 precipitable by ammonia, sodium phosphotungstate, potassium f erro- 

 cyanid, potassium mercuric iodid, or albumin. It gave positive 

 biuret, Millon, xanthoproteic and Molisch tests. In all these respects 

 the aqueous sol. of this precipitate agreed with the water-sol. of 

 sodium nucleoprotein. The precipitate obtained with o.i per cent. 

 hydrochloric acid sol., after purification, was extracted for twenty 

 four hours with 0.8 per cent. hydrochloric acid sol. Ammonia pre- 



*Eddy: Biochemical Bth-letin, 1913, ii, p. 435. 

 i°Eddy: Ibid., 1912, ii, p. 121. 

 11 Eddy : Ibid., 1913, ü, P- 435- 



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