The author has met with two cases of calcareous infiltration of the muscular substance of the heart, but they differed somewhat from each other. In one the lime salts were deposited in massive form, converting the muscular fibres into solid cylinders, while in the other there was a fine granular deposition, causing the fibres to resemble those in fatty degeneration.

In the one there were pale patches seen with the naked eye in the muscular substance, somewhat like those of fatty degeneration, but larger and situated in the superficial layers just under the pericardium. These patches had, even to the naked eye, a streaked appearance, the streaks following the direction of the muscular fibres and indicating that the condition affected the muscular substance. On cutting into the patches a gritty feeling was experienced, and under the microscope the appearances seen in Fig. 213 were visible. The muscular fibres were converted into solid cylinders which had a markedly crystalline appearance. Many of the cylinders were fractured transversely. On adding hydrochloric acid to these patches, there was an abundant evolution of gas and a solution of the lime salts. After the lime salts were dissolved the muscular fibres were restored so far as their outline was concerned, but their transverse striae were gone. The case in which this occurred was one of pyaemia, and it is probable that the arteries in connection with these patches had been obstructed, causing a necrosis of the portion of tissue which subsequently became impregnated with lime salts.

In the other case the condition was very different. A certain portion of the muscular substance of the left ventricle was found of a pale colour suggesting fatty degeneration, but the colour was continuous, and it was the external layers that were affected, and that mainly towards the apex. On microscopic examination the muscular fibres were found clouded with fine granules not unlike fat granules (Fig. 214). The granules, however, were dissolved by hydrochloric acid, but without evolution of gas. Koster has met with a somewhat similar case,. and he br -lieves that the salt here is, in part at least, sulphate of lime. In this case the true pathology of the condition was obscure.