Microscopists are indebted to Dr. Frances Elizabeth Hoggan for the description of a new method of staining, which we have found especially suited to the treatment of cartilage. The agent employed is _iron_, and the process, which is very simple, is as follows. Two fluids are necessary—(1) tincture of steel; (2) a two per cent. solution of pyrogallic acid in alcohol. A little of the former is to be poured into a watch glass, and into this the sections, after having been previously steeped in alcohol for a few minutes, are to be placed. In about two minutes the iron solution is to be poured away and replaced by solution No. 2. In the course of a minute or two the desired depth of colour will have been produced, when the sections are to be removed, washed in distilled water, and mounted in glycerine. The results obtained by this process are very beautiful, the colour produced being a very fine neutral tint, of delightful softness. The process also answers admirably in the case of morbid tissues, and we have now in our possession some sections of ulcerated cartilage tinged by the iron method, in which the minute changes resulting from the ulcerative disintegration are brought out with wonderful distinctness. As the structure of cartilage differs according to its purpose and situation, the student will find his time profitably employed in a careful examination of the following forms (α) _hyaline_—articular and costal; (β) yellow fibro-cartilage—epiglottis, or external ear; (γ) _cellular_—ear of mouse. Sections of the _intervertebral_ ligaments should also be made, in which the different kinds of cartilage may be examined side by side with each other. 29. _Coffee Berry_ affords sections of great beauty. The _unroasted_ berry should be soaked for hours or days in cold water until sufficiently soft; then imbedded in paraffine, and cut in the microtome (§ 12), the section being made in the direction of the long axis of the berry. Put up in glycerine, or stain rather strongly with carmine, and mount in balsam. The same method of treatment may also be applied to other hard berries or _seeds_. 30. _Fat._—Adipose tissue may be hardened in alcohol, cut in paraffine, and mounted in glycerine. If the tissue has been injected the sections may be mounted in balsam, and are then very beautiful objects, showing the capillary network encircling the fat cells.