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Use of collodion sacks for the crystallization of organic compounds
Dec., I()32.]
CURRENT ToPics.
773
merging well-cleaned bottles, pails, separator parts, etc. should be at least 50 when the time of action exceeds I minute, and at least ioo when the period is less than I minute. When applied as a spray, the solution should contain at least 200 parts per million of available chlorine. The solution must be clear, and should be used cold. J. S. H.
Use of Collodion Sacksfor the Crystallization of Organic Comp0unds.--HENRY TAUBER AND ISRAELS. KLEINER (.Tour. Chem. Ed., 1932, IX, I97O-I972 ) recommend the use of collodion sacks for the crystallization of organic compounds which have relatively high molecular weights and ordinarily do not dialyze. When a concentrated solution of such a compound (e.g. 20 per cent. maltose, io per cent. sucrose, lO per cent. lactose, IO per cent. tartaric acid, I per cent. cystine hydrochloride in 3 per cent. hydrochloric acid) is placed in a collodion sack, the open end is tightly closed, and the sack is suspended in the air, then crystals of these organic compounds deposit within the bag. Crystallization is comparatively rapid. Many inorganic salts diffuse through the wall of the sack and crystallize on its outer surface. J. S. H. Plastics.--( Chem. & Ind., 5 z, 868, 1932 ). Just recently, the Society of Chemical Industry welcomed as a new integral part, a Plastics Group. This is a sign of times. Ordinarily we look upon "Plastics" as synthetic organic compounds which, under the influence of heat and pressure, become plastic and moldable into desired forms and shapes. Very often such treatment produces a setting-up action within the plastic material and it becomes rigid and permanently non-plastic under all subsequent conditions. Chronologically, clay probably is the oldest known plastic material. Rubber is well known and so extensively applied it can be considered as in a field by itself. H. V. PATTER, the author of this paper, has limited himself to a discussion of the synthetic organic plastic substances. Celluloid, probably the best known of all, is prepared by first treating cellulose with a mixture of strong nitric and sulfuric acids. This treatment produces a nitrocellulose which when plasticised with camphor gives "Celluloid." This is insoluble in water and becomes plastic at about the temperature of boiling water whereupon it may readily be molded into shapes that retain their contour when cooled. Celluloid was first prepared commercially in I869 and is still the most important cellulose derivative from a commercial point of view.
CURRENT ToPics.
773
merging well-cleaned bottles, pails, separator parts, etc. should be at least 50 when the time of action exceeds I minute, and at least ioo when the period is less than I minute. When applied as a spray, the solution should contain at least 200 parts per million of available chlorine. The solution must be clear, and should be used cold. J. S. H.
Use of Collodion Sacksfor the Crystallization of Organic Comp0unds.--HENRY TAUBER AND ISRAELS. KLEINER (.Tour. Chem. Ed., 1932, IX, I97O-I972 ) recommend the use of collodion sacks for the crystallization of organic compounds which have relatively high molecular weights and ordinarily do not dialyze. When a concentrated solution of such a compound (e.g. 20 per cent. maltose, io per cent. sucrose, lO per cent. lactose, IO per cent. tartaric acid, I per cent. cystine hydrochloride in 3 per cent. hydrochloric acid) is placed in a collodion sack, the open end is tightly closed, and the sack is suspended in the air, then crystals of these organic compounds deposit within the bag. Crystallization is comparatively rapid. Many inorganic salts diffuse through the wall of the sack and crystallize on its outer surface. J. S. H. Plastics.--( Chem. & Ind., 5 z, 868, 1932 ). Just recently, the Society of Chemical Industry welcomed as a new integral part, a Plastics Group. This is a sign of times. Ordinarily we look upon "Plastics" as synthetic organic compounds which, under the influence of heat and pressure, become plastic and moldable into desired forms and shapes. Very often such treatment produces a setting-up action within the plastic material and it becomes rigid and permanently non-plastic under all subsequent conditions. Chronologically, clay probably is the oldest known plastic material. Rubber is well known and so extensively applied it can be considered as in a field by itself. H. V. PATTER, the author of this paper, has limited himself to a discussion of the synthetic organic plastic substances. Celluloid, probably the best known of all, is prepared by first treating cellulose with a mixture of strong nitric and sulfuric acids. This treatment produces a nitrocellulose which when plasticised with camphor gives "Celluloid." This is insoluble in water and becomes plastic at about the temperature of boiling water whereupon it may readily be molded into shapes that retain their contour when cooled. Celluloid was first prepared commercially in I869 and is still the most important cellulose derivative from a commercial point of view.