JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS hand, one should realise that when gelatin is placed in cold water, in which gelatin does not dissolve, the water, in diffusing into the sheet, causes the gelatin to swell so that the intermolecular spaces are enlarged and the water molecules will not get jammed at the surfaces. Even a relatively thick sheet of gelatin will soften and swell in cold water in a comparatively short space of time. Only when the gelatin has fully imbibed water should heat be applied. Under these conditions, as soon as the temperature reaches the melting point of the swollen gelatin, the whole mass will quickly disperse. Solving the "why" and the "wherefore" brings us now to the quintessence of looking. Nobody imagines for one moment that Isaac Newton was the first man to see an apple fall. It is true, however, to say that he was the first man who really looked at an apple falling because he started to ask himself questions as to why all apples fall and, indeed, all heavy things behave in a similar manner. He observed that it was a characteristic of nature and, being Newton, he was able to see that the falling of the apple was due to an attractive force existing between two masses. It is all very simple now, and although even before Newton's time the principle of failing weights was employed as a source of energy, it was done merely by virtue of experience and not by knowledge. What it really comes to is that the observant and thoughtful person, whenever he sees something happen, always enquires of himself why did it happen. If he is a good scientist he will not let his mind forget that happening until he has produced a hypothesis to explain in a reasonable manner the phenomenon. What all this really means is that every time one looks at anything, veritable avalanches of messages should be passing from the eye to the brain, from the brain to the eye, so building up a complete co-ordinated picture. It is this form of approach which produced the craftsman of the past. Although he is being succeeded by the scientist, the methods must still remain true in principle, and the task of the industrial scientist is to transpose these observations into figures or values. By such a means of notation it becomes possible not exactly to dispense with the craftsman, but by having scientific data one is able to make experience permanent. The chemist in the factory has the great chance. Most products--cer- tainly those made by reputable firms--are good, even very good. Since no one should ever be content to rest on his laurels, it is necessary to aim at better quality produced by a simpler technique or an alteration in formula, etc., etc. Because it is impossible to make a tremendous improvement in something which is already very good, means have to be devised so that the improvement can be determined. It is clearly to be seen that such variations can be determined only by a statistical examination of values relating to quality. It is almost certain that every chemist records all his analytical data relating to quality control. Often such information is meticulously 156

LOOKING AT THINGS set out in expensive, high quality books indicating that the records are considered to be of value. Unfortunately, such books are often closed and their usefulness is greatly curtailed since trends in day-to-day production can be seen only by statistical examination. In the final appraisal, of course, mathematical treatment is necessary, but it demands examination of the figures at regular intervals. It also takes time and the findings may be such that they sort of close the stable door after the horse has escaped. Further, the statistical examination must be done properly and by a competent statistician, for it must be clearly recognised that the correlation of one set of values against another must conform to certain requirements which hax e been adequately investigated by those adept at statistical evalua- tion, and it seldom behoves a novice, unless he be a first-class mathematician, to dabble in this sort of work. The alternative is, however, much more simple, and although it may often lack that precision which the mathematical treatment of the results can give, it will help considerably in the work of controlling quality. It consists of a form of graphical representation. In most of the executive offices of firms it is customary to see, plastered on the wall, graphs showing the daily production and other things. It is worthy of comment, however, that these graphs are all of a type. They are, in fact, graphs in so much as the person interested insists on joining the individual points. This is no sort of business. Its fatuity is well shown by the mere fact that the lines zig-zag with dizzy insistence up and down the paper with time on the bottom axis. To a scientist, a "graph" is a repre- sentation of values which are plotted out in order to show a trend or a relationship. Actually, although time is a very important factor, the graphs have fundamentally little or no relationship with time, and certainly as regards the values obtained in a control laboratory the time at which they were done is often of little moment the value of time only lies in enabling complaints or, what is perhaps more unusual, letters of appreciation of quality to be identified with a particular group of determinations. Since this form of expression is to be used in a statistical manner, it is obviously of importance that as many determinations should be done on each day as is within the power and time of the chemist, and all these points must be indicated on the graph. It is advisable to have the daily spacings close together so that a graph can last for a long period of time. In doing this it has also the merit, which will be easily appreciated, of enabling the variations to be seen more clearly. The method adopted should be a series of marks the first determination should be a black spot or dot and the spacings on the ordinate should be of a distance which has some relationship to the expected experimental error. Where two points fall on the same dot then the fact that it is a dual dot should be indicated by putting a tiny dash to the dot. Each result which fits on this precise spot should be indicated by an addi- tional dash, as, for example, . • L _• +'fi'. ....... ...•(- In this way many 157