In the analysis made by Dr. Bostock of the dorsal vertebrw of a woman affected by mollities, he found, that the proportion of the earthy constituents amounted to only one-fifth of the whole weight in one part of the bone, and to one-eighth only in another ; while in a healthy bone from the same part, they amounted to more than one half the whole weight.* In the analysis given, in Rokitansky's work before cited, of a portion of bone fected with this disease we find—in 100 parts : Phosphate of lime and magnesia - 17-48 Carbonate of lane and soluble salts 6.32 Total of inorganic matter 23'80 Cartilage vessels and fat - 76'20 Specific gravity of the bone 0.721.
Among the reasons adduced in favour of the supposition that this disease is sometimes a malignant one, besides the general and violent pains that usually precede the deformity, its incurability and unchecked course towards a fatal termination, have been given. That this result is not invariably the case, the fol lowing ease quoted from Naegele will show, in the fact that the pelvic bones had regained their normal hardness. In the pelvis whence the foregoing analysis vvas taken, the bones had, most probably, at some former period been much softer than they were at the time of death. Such cases also show, that though very frequently, the pelvic bones distorted by mollifies are so soft and pliable as to yield, sometime.s' considerably, to the fiEtal head ; yet that this is by no means always the case, nor should it be taken, as it is by some ob stetricians, as a characteristic mark of this disease affecting the pelvis.
A very minutely detailed case of pelvic dis tortion, resulting clearly from one or other kind ofmollities ossiuin, is given by Naegele.* The subject of the case, after having borne six children (five healthy, full sized, and living, and the sixth still born), became affected with this disease, which brought about such exten sive pelvic distortion and contraction, that, at the seventh labour, the Cxsarian operation was rendered necessary, from the conse quences of which the patient died after the fourth day. The shortness of the tirne in which the pelvis became so much distorted, together with the extent of the deformity, and the fact that, at the time of the patient's decease, it hacl regained its normal hardness, render the case a very remarkable one. Naegele considered it as the most contracted pelvis that had ever come under his observa tion.
The anterior wall was pushed upwards and the 'posterior downwards, the superior plane being bent at the acetabula, so that the upper border of the pubic symphysis was level with the upper surface of the 4th lumbar vertebra ; and a line drawn from one anterior superior iliac spine to the other, cut the upper surface of the 3rd lumbar vertebra at its posterior half. The innominate bones were
pushed together, and presented the acute fur rovr, like cracked pasteboard, on their inner surfaces. The sacrum was bent almost double. The inea.surements are given by the author, as follow From the anterior inferior iliac spine, to the opposite point on the iliac crest postenorly— on the left side, 2 inches 4 lines ; on the right side, 2 inches 6 lines. From the apex to the upper surface of the sacrum, 16 lines only ; to the junction of the 1st and 2nd sacral pieces, 101 lines. From the left superior pubic ramus a little internal to the pectineal eminence, to the body. of the 4th lumbar vertebra on the same level, on/y 21 lines. Between the same points on the right side, Gf lines. The sides of the subisubic arch were only 3 lines apart, and more contracted near the sciatic tuberosities than above, by these processes being pushed inwards. The pubes in this pelvis, as rept.e seated in the drawings given by the author, are bent in the middle of their superior rami, thus producing the rostrated form.
A like case of progressive pelvic deformity from mollifies ossium is described by Dr. Cooper.* The patient, Elizabeth Foster, had perfectly easy delivery in her three first labours ; before the fourth, she had, while pregnant, rheumatic fever, and afterwards constantly suffered from universal pains of a rheumatic character, followed by gradual spinal distortion. From the fourth to the sixth labours, they were increasingly difficult, and in the se venth and eighth she was obliged to be delivered by craniotomy, the saero-plibic diameter being reduced to 2 inches. Three years after, she ag,ain became pregnant, when the sacro-pubie diameter was found to be reduced to 11 inch, becoming gradually narrower on each side. Cmsarian section was performed, under which she sank. After death, the sub-pubic arch was found to be so much contracted, that the sciatic mini were little more than 1 an inch apart. The pelvis was so soft and spongy, that the finger could be easily pressed into its substance, and at the place of attachment of some or the muscles, the osseous substance was found raised into etninences, as if pulled out.