A discussion of the microscopic appearance of ketchup in terms which can be readily understood by manufacturers is not an easy task, as it necessarily involves technical knowledge. The subject has become one of importance, owing to the attitude of many food officials in enforcing a microscopic standard for this product, and on the part of many brokers in requiring a guarantee to comply with this standard in making purchases. Many manufacturers have either assumed or found it necessary to have their finished products examined. Some employ “experts” to make the examinations in their own plants, while the majority send their samples to commercial laboratories. The total tax upon the industry for such work amounts to thousands of dollars annually. The result of the work as a whole has been beneficial, as any effort is which attracts attention to details. It has likewise been the means of causing much unpleasantness and not infrequently loss, because of lack of understanding on the part of both manufacturer and examiner as to the cause of certain findings. The manufacturers have proceeded in the usual way without sufficient knowledge of what the resultant product will be unless there is careful supervision of material and methods, while too frequently the examiner is neither experienced in technique of the examination nor in the effects of the different steps in manufacture upon the product. Furthermore, much distrust in microscopic finding is evinced when a half dozen or more samples from the same batch, sent to as many persons, result in as many different reports. It naturally causes a lack of confidence in both paid examiners and in food officials, though those who make these examinations may be absolutely honest in their findings. In order to clarify some of the points, it has become necessary to go into detail, into both the method of examination and into the effect produced by manufacture. A scientific method of food examination is necessary for food officials in order to determine the condition of a product, but is not necessary for the manufacturer, though it may be advantageous. The latter is in a position to know what enters his factory and what changes take place in the food until it reaches the sealed package. He should have no fear of a method which correlates the findings in the finished product with that of the material used and the changes due to treatment. Undue importance may seemingly be given to the subject of ketchup, but the principle involved applies as well to other products.