August 12, 1921] 



SCIENCE 



137 



influences the vapor tension of the nitric acid. 

 The hydrolyzing action of sulphuric a«id in the 

 nitrating bath sets up secondary reactions, which 

 are responsible for variations in yield, formation 

 of insoluble bodies, gelatinous products, and un- 

 stable esters. The solubility of nitrocellulose is 

 determined by the dehydrating value of sulphuric 

 acid in the nitrating bath. The nitrocelluloses 

 used in the commercial world are divided into 

 seven types based on their specific uses. Degree 

 of nitration curves based on factory experience, 

 showing the degree of nitration as a function of 

 the actual nitric acid and the nitrating bath, indi- 

 cates that, for the same degree of nitration, as 

 the actual nitric increases a corresponding increase 

 in the nitrating total is required in order to main- 

 tain the same molecular ratio between the water 

 and sulphuric acid in the bath. 



Some commercial possibilities of corn cob cellu- 

 lose: F. B. LaForge. Brief outline of our process 

 for the preparation of adhesive, furfural and 

 cellulose from corn cobs; proposed uses of the 

 three products. Preparation of corn cob cellulose 

 in powder form and uses as substitute for wood 

 flour for nitration and acetylation; preparation 

 in the form of pulp and uses in paper manufacture. 

 Corn stalks and husks as a source of adhesive 

 furfural and fiber. 



A color test for "remade milTc" : Oscar L. 

 EvENSON. A yellow color produced by the action 

 of sodium hydroxide on the washed curd of milk 

 made, from milk powder, serves as a test for the 

 presence of milk powder in natural milk. The 

 ourd precipitated from 25 c.c. of milk with acetic 

 acid is washed and placed in a vial with 10 c.c. 

 of 5 per cent, sodium hydroxide. Natural pas- 

 teurized milk treated in the same manner is used 

 as a control. The color is probably due to the 

 presence in the curd of a residue of aldehydic 

 nature resulting from the action of heat and 

 desiccation. 



Nitro-cellulose and its solutions as applied to the 

 manufacture of artificial leather: W. K. Tucker. 

 (1) Properties of the nitro-cellulose: (o) Degree 

 of nitration and why lower and higher nitrations 

 are objectionable; (6) viscosity; (c) degree of 

 purification and the effects of the purification on 

 viscosity; (d) stability; (e) ash. (2) Solution: 

 (a) solvents and non-solvents generally used and 

 why; (&) viscosity of solutions generally used. 

 Granular and short solutions; (c) effect of va- 

 rious solvents and non-solvents on the viscosity 

 of solutions; (d) proportion of nitro-eellulose in 



solutions generally used and short discussion of the 

 use of solution with a larger percentage. 



An experimental study of the significance of 

 "lignin" color reactions: Ernest C. Croker. An 

 investigation of the so-ealled color reactions showed 

 that the following phenols gave strong red, violet 

 or blue colors with wood of any kind when applied 

 in strongly acid solution: phloroglueinol, orcinol, 

 resorcinol, and pyrogallol. Likewise, all primary 

 aromatic amines gave yellow to orange colors when 

 applied in acid solutions of any strength. The 

 secondary amine, diphenylamine, also gave an 

 orange color even when highly purified and freed 

 from traces of primary amines. Pyrrole gave a 

 deep red color in hydrochloric acid solution. Va- 

 rious materials were substituted for wood, and 

 tested with above types of reagents for color 

 formation. It was found that only (but not all) 

 aromatic aldehydes gave color reactions similar to 

 those given by wood. Spectroscopic investigation 

 and comparison of colors obtained showed that 

 the principal color source of wood is not vanillin 

 or furfural, as several writers have claimed, but 

 a different aldehyde — possibly coniferyl aldehyde. 

 It was found that certain natural phenols and 

 ethers such as eugenol and safrol, which are re- 

 ported as giving colors with the phenols and al- 

 dehydes, do so only because of aldehydic impuri- 

 ties. The Maule test was found to give a distinct 

 red color only in the case of deciduous woods. The 

 test was found to be caused by a component of the 

 wood, which after chlorination turns red when 

 made alkaline. Apparently no color test is an 

 indicator of lignin, but of traces of materials (al- 

 dehydic for most of the tests) which usually — 

 perhaps always — accompany lignin. 



A proposal for a standard csllulose to be avail- 

 able for research: B. Johnsen. 



A discussion of some beater furnish reactions 

 from the standpoint of colloidal chemistry: Jessie 

 E. Minor. This discussion is based upon a series 

 of experiments performed for the purpose of ob- 

 taining some more exact information as to the 

 changes in the physical properties of a paper which 

 are brought about by each addition made to the 

 furnish. The increased strength attained by beat- 

 ing is due to the mucilaginous product of hydroly- 

 sis and the decrease in strength by excessive beat- 

 ing is due to the loss of fiber structure. Alum 

 coats the fiber with a gelatinous layer of aluminum 

 hydroxide and changes the electrical charge on the 

 fiber. It thus aids in size retention as does calcium 

 sulphate, though the latter is less effective. In- 



