Nov.,
191.5
T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING CHEMISTRY
The successful manufacture of the photographic film has been a great achievement for the chemist. Especially is this the case when the motion-picture film is considered. The problem of making thousands of miles of the support, of uniform high quality, and coating this with an emulsion of uniform and maximum sensibility and satisfactory stability, is one with which the chemist has had many a struggle, and for the solution of which he is entitled to much credit. The advance in the manufacture of dry-plates in the quartercentury has been remarkable. I n uniformity, keeping power, speed, and most of all in color-sensitiveness, their quality has been steadily improving. Much of this improvement has been due to the careful chemical studies of the emulsion, both in the factories and in the I(. I=. Graphische Lehr- unci VersuchsAnstalt, in Vienna, where a notable group of chemists have devoted themselves to a thorough study of all phases of the photographic industry. I t is due to chemical research work of a high order, that we now have panchromatic plates which are sensitive over practically the whole range of the visible spectrum, and can even photograph the infra-red rays which our eyes do not perceive. The beautiful three-color work in our modern magazines would no more be possible without the panchromatic plate, than would modern press photography without the high-speed plate. In color photography we have made considerable progress. The solution, by the Lumiere Brothers, of the problem of the manufacture of a plate combining a permanent screen in three colors with a stable panchromatic emulsion, first brought natural-color photography within the reach of any well-informed photographer. Many similar plates have been introduced, and the results with this type have had a great value in many lines, particularly in medical science. Other processes for transparencies, such as those of Ives and the Eastman Kodak Co., and several for the production of natural-color prints on paper, owe their development and perfection to chemical research of a high order. Suitable aniline dyes for sensitizing the panchromatic emulsion are of course the fundamental need of all such processes, but the proper selection and adjustment of filters, color-screens, and other factors to the characteristics of the panchromatic emulsion chosen, involve a mass of careful work. The chemist has made for us a large number of new developing agents, which have many advantages over the old-fashioned pyrogallic acid and ferrous oxalate. Improvements in the quality and uniformity of other chemicals have been greatly appreciated. As yet we are somewhat in the dark as to the exact nature of the latent image, the theory of the action of some of the constituents in the developer, and many similar things, for enlightenment on which we must turn to the chemist. It is a very encouraging sign of good things to come, that one of the largest photographic manufacturers in the world has installed and is maintaining a large research laboratory, where chemical and physical research work on all phases of photography is being carried on by a corps of thoroughly trained men who are in touch with actual manufacturing conditions. We may certainly expect that the next twenty-five years will bring us many more great developments in photography, through the work of these and other chemists and physicists. U N I V E R S I T Y OF h I I K N E S O T A ,
MINNEAPOLIS
CONTRIBUTIONS OF THE CHEMIST TO THE MANUFACTURE OF PHARMACEUTICAL PRODUCTS B y FRANK R . ELDRED Chief Chemist, Eli Lilly & Company
The manufacture of medicines is not confined t o pharmaceutical houses, since they do not produce many of the medicinal chemicals, volatile oils and other products which may be said
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to constitute a large portion of their raw materials. Many of these products, however, must pass through the hands of the pharmaceutical manufacturer in order that they may be put in a form suitable for use. It is not easy t o draw the line between pharmaceutical manufacturing and the closely allied industries as their fields of activity will frequently be found to overlap; for instance the study and manufacture of certain alkaloids have been left almost entirely to pharmaceutical chemists and manufacturers although most of the alkaloids have been produced by distinctively chemical manufacturers. Few industries have been as dependent upon the work of the chemist as that of pharmaceutical manufacturing. Many industries have been developed up to a certain point without the direct assistance of the chemist but the very beginnings of pharmacy and chemistry were closely linked together and pharmaceutical manufacturing was made possible by the work of the early chemists. It is true that pharmaceutical manufacturing has not always kept pace with the progress in chemistry, yet the chemist, although a t times very imperfectly trained, has always been an indispensable factor in the development of the industry and to-day the successful manufacturers are those who are making use of the most recent discoveries in chemistry and medicine and to that end have built up organizations of well trained and highly specialized scientific workers. The work of the chemist in the pharmaceutical industry has been characterized by the development of new products and improvement in the quality of products already established rather than by any reduction in manufacturing costs, although a t the present time much attention is also being given to the latter problem. For many years i t has been the custom of the more progressive pharmaceutical manufacturers to de\-ote considerable sums of money to research along the various lines connected with their business and for this reason much of the credit for the development of our present materia medica should be given to them. Chance and uncertainty in pharmaceutical manufacturing have been largely eliminated, and while ten or fifteen years ago much of the routine manufacturing could be carried on without the direct supervision of the chcmist, i t is now necessary to have every crude material thoroughly examined, every process controlled and every finished product assayed or inspected by competent chemists. Smong the earlier improvements, due entirely to the pharmaceutical chemist, the standardization of preparations made from vegetable drugs deserves especial mention. The crude drugs were found to vary enormously in strength and as their active principles became known and assay processes were developed the manufacturers adjusted their preparations so that they were always of uniform strength. At that time the only pharmacopoeial standard for such preparations was the fixed amount of drug used in their manufacture and the preparations when finished of course varied according to the strength of the drug frdm which they were made. The standards established by the manufacturers were based upon the strength of an average prime drug and the quantity of drug required varied inversely with its strength. Most of these standards were adopted by the Pharmacopoeia many years later. This like many other improvements made by the chemist in this industry resulted in increased costs not only on account of the analytical work required but also because of the greater care necessary to maintain these standards. Thousands of different products are manufactured by every pharmaceutical house, and it has been the duty of the chemist during the past twenty-five years to study these products in order to discover their faults and improve them by modernizing the methods of manufacture. On account of the great number of products to be studied and the diverse problems involved, progress may seem slow but if we look back even ten years we
