Now for an example or two where the microscopist has the advantage of the chemist. Some jam makers have been known to be sufficiently unscrupulous to sell “raspberry” jam contaminated with a large percentage of some cheaper fruit, such as gooseberry. The seeds of the two fruits differ so markedly that it is really not necessary to employ a microscope to discover the fraud, but a case is on record where wooden seeds were used, so like the true seeds of the raspberry, that a very careful examination was necessary to show what had happened. In our chapter on the Microscope in Agriculture we have referred to this point in greater detail. Starch of various kinds is a very common food adulterant and the experienced microscopist can estimate almost precisely, the proportions of different starches in a mixture, a feat which would sorely puzzle the chemist. So in certain cases the microscope is indispensable. Briefly the microscope is a time saver; chemical tests occupy a considerable time; microscopic examination is quick, the experienced microscopist at once recognises what he observes. Very small quantities can be examined under the microscope, relatively large quantities are required for chemical tests. Again, if only a small quantity of the material is available for examination and it is necessary to carry out chemical tests, they can be performed under the microscope and this point is considered in another chapter. We have mentioned that starch of various kinds is a common adulterant of many foods and the budding food analyst might do worse than learn to recognise the various starch grains under the microscope. They are easily obtained and as easily observed. Each variety of starch has grains which are remarkably constant in their characteristics. A beginning may profitably be made with potato starch, for its grains are large and they possess certain well-marked features, which may or may not be present in the grains of other starches. By scraping the newly cut surface of a potato we can obtain thousands of starch grains. The surface of the potato must not be grated, just a gentle scraping with a pocket knife and a mere speck of the cloudy liquid that is obtained, added to a drop of clean water on our slide, will suffice. Cover the object with a cover glass and examine under a fairly high magnification. There are countless, oval, almost transparent bodies in our field of view, they are potato starch grains. Each one, as we shall see when we make a more careful examination, is not unlike a miniature oyster-shell. In the shell, there is a point which is its oldest part and the remainder has grown, layer by layer, round that point till the shell is fully formed. Now we magnify the starch grains as highly as possible and slowly rotate the fine adjustment to and fro, for the reason that the object is not flat and by doing so, we obtain all its parts in focus in turn. If the illumination is not too intense,