7:40 IHILOSOPHICAL TRANSACTIONS. [aNNO 1/80. 



bony matter, in irregular forms and of different sizes, were found in the water 

 at the bottom of the pan ; and as no force, nor even motion, had been used 

 which could have separated this matter from what remained adherent to the bone, 

 it is highly probable it was ever deposited in, and dispersed through the tumor in 

 a detached state. The tumor externally bore the usual appearances of a diseased 

 or enlarged gland ; but, by degrees the whole appearance was changed, and the 

 bony matter, as the maceration proceeded, seemed surrounded by a hard, 

 white, and rather transparent substance, not much unlike suet, in which state 

 it principally resisted tlie dissolvent power of the water. When the bone in 

 general seemed sufficiently cleansed for drying, there were in one part some re- 

 mains of this suety substance ; but on exposing it to the open air, in tlie course 

 of 3 days it was entirely dissipated, scarcely a trace of it remaining, unless that, 

 in the particular portion alluded to, the bony matter was of a more dusky 

 colour than elsewhere. 



The left os innominatum now appeared perfectly free from any unnatural ap- 

 pearance in every part, even to its junction at the symphysis of the pubis; but 

 there the line was drawn, and disease immediately began to show itself through 

 the whole of the right os innominatum, and to advance as it were from a super- 

 ficial ulceration to excrescences in the greatest quantity. It is remarkable that 

 the cartilage connecting the ossa pubis should be so complete a boundary to the 

 disease ; for though the external lamella was in all that part of the os pubis and 

 ischium (particularly at the ramus of the latter) which united forms the foramen 

 ovale, not the least deficiency was to be observed in the left os pubis. So inte- 

 resting to the knowledge of the nature of this disease is it to observe that the 

 extent of the tumor, which terminated exactly at this part, should likewise as 

 exactly have limited its effects or consequences. 



So far then as the external lamella of the os pubis and ischium was deficient, 

 so far these bones presented that roughness and irregular loss of substances, 

 which is commonly denominated ulceration or superficial caries. The bottom of 

 the acetabulum had likewise suffered in a similar manner : but over the whole of 

 the ilium, both externally and internally, the lamellae seemed very little injured, 

 though covered by vast quantities of bony matter branching out into various 

 forms of different sizes, which a minute examination and careful attempt to 

 separate ascertained to be mere, though firm, adhesions to the surface of the 

 bone and adventitious to the part on which they were found, 



XXX IF. Thermometrical Experiments and Observations. By Tiberius Cavallo, 



F. R. S. p. 585. 

 Mr. C. having been appointed by the President and Council of the r. s, to 

 write the annual dissertation, pursuant to the institution of Henry Baker, Esq. 



