July 20, 1926
INDUSTRIAL AND ENGINEERING CHEMISTRY
Biological Processes and Frothing Agents B Y EDWARD THOMAS 165 Broadway, New York City
If a drop of cresol or melted phenol is placed in a flat-sided quart bottle half-full of water and the bottle is violently shaken, a froth forms on the surface. The name mineral-frothing agent applied to cresol, phenol, and to a large number of other frothforming substances, is, however, only partially descriptive. Prior to the formation of the froth another phenomenon is observed— the body of the water is seen to be full of microscopic and almost microscopic bubbles which persist in the body of liquid, slowly rising to the surface and gradually forming the froth. The bubbles jostle each other, and their action towards each other is like that of living cells. It is not strange that microscopic froths viewed b y biological students have often misled observers into believing that these were new forms of cell groups. This resemblance of the actions of bubbles and cells to other bubbles and other cells leads to t o e formulation of the generalization that mineral-frothing agents cause bubbles to behave towards each other in the same way that groups of cells behave among themselves. Phenol and cresol, two of the most effective mineral-frothing agents, although poisonous, are well-known safe disinfectants. Further examination of a table of mineral-frothing agents disclosed that all of the mineral-frothing agents that are poisonous are also safe disinfectants. Many essential oils are poisons but are safe disinfectants. Moreover, so far as known, every essential oil of the vegetable kingdom is a good mineral-frothing agent—as if the oil played a useful part in the life processes of the plant producing it—aiding the cells in their working together. Another parallelism between the action of mineral-frothing agents and biological functions may be mentioned. Salt water, ocean water, is a mineral-frothing agent. It has been used commercially in concentrating copper ore and also in concentrating coal by froth-flotation. Anyone, who has carefully observed the wake of a rapidly moving boat or t h e waves thrown off by a boat in salt water, has noticed the fine bubbles which form beneath the surface persist, rise, and become floating froth. Salt-water solution which forms the basis of the blood and i t s stream of •cells, being a mineral-frothing agent, facilitates the group functioning of the blood cells. One of the best mineral-frothing agents, in fact the one first used both commercially and in research, is oleic acid. Oleic acid is said to be formed in the process of digestion. It seems likely that its little understood property, which causes it to be termed a mineral-frothing agent, is related t o the process of assimilation, very likely by affinity-controlling properties. Beyond this group of observed facts it seems impossible to progress except by hypothesis. Venturing the hypothesis that we should expect to find a disease not dependent upon the presence of germs, but dependent upon the presence of something which causes the cells themselves t o produce an abnormal mineralfrothing agent, our attention is turned t o tumors. A recent oh server reports finding lactic acid in tumors, more i n malignant than in benign tumors. Lactic acid is well-known i n the laboratory as a good mineral-frothing agent. From this may be drawn the suggestion that the therapeutic control of tumors will probably be attained through control of autogenously produced lactic acid and perhaps some other mineral-frothing agents. Here is where the writer, a patent attorney and a student of chemistry, must stop and turn his suggestions over to the biologists to verify, disprove, or carry forward. One all-important suggestion, however, he would leave as a warning; many frothing agents are not mineral-frothing agents. Saponin, for example, widely used to produce froth on beverages, is not a mineral-frothing agent. It is useless in concentration of ores b y froth-flotation. For some unexplained reason it is unlike phenol, cresol, and oleic and lactic acids. They cause valuable metallic sulfides to adhere to the froths they produce, but allow gangue material to ' drop. Saponin makes no such selective separation. Saponin is said to be poisonous but it is not generally classed as a safe disinfectant. Ordinary soap solutions also are not mineral-frothing agents, although some soap solutions form fine-appearing froths utterly useless for the selective action required in froth-flotation. Biologists should also be warned that some substances, such as potassium xanthate which are not mineral-frothing agents themselves, have the property of vastly increasing the efficiency of some mineral-frothing agents. For example, a solution containing 0.003% potassium xanthate sometimes enables one tenth of a pound of pine oil to have the froth-flotative effect o f two pounds formerly required in the absence of the xanthate. Under some other conditions the addition of as little as one pound of the sulfate of copper known as blue vitriol to three tons of water vastly improves the efficiency of froth-flotation. A mixture of mineral-frothing agents is often found to be more effective than would be expected from tests of individual components of the
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mixture. Probably parallel phenomena will be found in biological research. The correlation of facts here presented seems to offer problems suitable for further research by biologists along two lines: One is the connection between the property of frothing and the working of animal and plant life. Another is the connection between the kind of selectivity meant by the term mineral-frothing when applied to a frothing agent and the selectivity of disinfectants and of metabolism-controlling substances. Only experimental research will result in a sure-footed advance in the branch of science under discussion.
Venable Hall Presents Novel Construction Features Venable Hall, the new chemical building of the University of North Carolina occupied during the past academic year, was designed along strictly utilitarian lines. Its academic Georgian facade forms an ell with its south wing enclosing roomy laboratories built according to modern industrial patterns to give maximum light, free space, and ventilation. The adoption of the saw-tooth roof, so familiar in industrial buildings, for an academic science building accomplished several important things and at the same time typefies the intensely practical point of view of modern science as contrasted to its cloistered predecessors. Not only was natural lighting and ventilation easily secured by it but the cost of construction, ordinarily a very important item in the design of academic buildings, was materially reduced as compared with other types. By locating all the large laboratories upon a single floor under such a roof, too, the accomodation of large numbers of students from a single large stock room was much simplified. The allotment of space to the variety of purposes required of the building has been happily accomplished to minimize the damage and discomfort that might be caused by any serious evolution of objectionable fumes. Within the facade which forms the front of the building are located class rooms, executive offices, museum, and library so that nothing in this section is likely to cause, or be damaged by, the ordinary casualties to which a working laboratory is subject. The south wing contains the smaller special laboratories, private offices, and laboratories for the instructional staff and individual laboratories for research workers, while in its extreme end, as far as might be from the executive offices and the lecture rooms in the front of the building, is located the engineering practice laboratory where semi-commercial operations are carried on. Within the ell itself under the saw-tooth roof are located the laboratories for large classes and in the very center is the large lecture room for general chemistry. Such an arrangement provides maximum safety and convenience. The building is completely equipped at the present time to care for 1064 students in laboratories and 420 others in lecture rooms at the same time, in addition to providing office and private laboratories for 8 members of the faculty and 36 graduate research students. By using the general laboratories in shifts as intended and completing three rooms, as yet unfurnished, working space is provided for a total of 1674 students in general, analytical, and organic chemistry. These things are accomplished in a building containing 56,000 square feet of floor space which cost $315,000, excluding furniture and piping, an average of $5.60 per square foot or approximately $.50 per cubic foot.
New Process for De-Inking Old Paper A German claims to have invented a practical method of removing printing ink from old or scrap paper, reports the Chemical Division of the Department of Commerce. His method is based on the employment of an alkali, such as caustic soda, and of a flotation agent, such as tetralin (tetrahydronaphthalene). In order to remove the last globules of tetralin, recourse is had to centrifugal force. The tetralin is reclaimed by filtration or distillation and returned to the process. Real progress is being made in this country in the manufacture of latex treated paper. The tops of a number of taxicabs went through the past winter covered with latexed paper converted into artificial leather by the addition of a lacquer coating. Bookbindings made of similar material are highly successful and other startling developments may be expected soon. The committee plan of government is rarely successful on account of the division of authority. However, we were recently assured that such a plan applied to the research program of a large pharmaceutical manufacturer, involving the cooperation of experts in medicine, chemistry, pharmacy, pharmacology, biology, and other sciences, is operating beautifully.
