VOL. LII.] PHILOSOPHICAL TJRANSACTIOXS. SSQ 



practice. In nervous disorders, and in fevers of the putrid malignant kind for 

 instance, we find the heart so extraordinarily weakened, that it is in many in- 

 tances dangerous to subject the patient to an erect posture, even though it be 

 but for a very little time. Syncopes, and even fatal deliquia and comatose affec- 

 tions, have been the consequence. In scurvies too, where the whole system is 

 become very lax and tender, and has lost much of its tonic and vital elasticity, 

 the same phenomena have occurred. In these cases the necessity of the hori- 

 zontal, or at least the recumbent posture, is manifest; as it is obvious how much 

 more force is requisite to throw the blood up into the head in an erect than in a 

 horizontal position. 



It is probable that the extreme weakness and slow recovery of some women, 

 particularly such as are of a delicate constitution, after a hard labour, depends 

 often on the weakness of the heart, occasioned by the force it sustained during 

 the throws of labour. In these cases, though rest is among the first methods of 

 recovery, yet Mr. P. thinks he had observed the use of the quinquina to be at- 

 tended with good success. 



To conclude, it is probable that cases of this kind occur much oftener than we 

 are aware of; as doubtless the dissection of morbid bodies, were that but more 

 frequently allowed of, would teach us. There is room to think that this is the 

 case, though not in the degree of the instance before us, in almost all diseases 

 arising from a weak and lax fibre. Cheselden tells us, in his Anatomy, that in 

 persons " that died of a dropsy, he always observed the heart large, its fibres 

 lax, and the vessels about it immoderately distended." 



Aristotle expressly says, that timid people, and those of cold constitutions, 

 have large hearts; on the contrary, that the bold, and those of a warm temper- 

 ament, have small ones. Nor does this opinion of that excellent philosopher 

 seem ill founded, as women, children, and weakly men, from whom much cou- 

 rage is not looked for, are lax fibred, and consequently more liable to an enlarge- 

 ment of this organ, than those who are robust and tense fibred, from whom a 

 manly exertion of courage is more to be expected. 



LV. On several Experiments in Electricity. By Edw. Delaval, Esq., F. R. S. 



p. 353. 



It appears by the experiments mentioned in my letter, published in the 51st 

 volume of the Philos, Trans, that stones, and other earthy substances, are con- 

 vertible by several methods, and particularly by diflferent degrees of heat, from 

 non-electrics into electrics. Since that time it has been the opinion of some 

 persons, that this change does not immediately depend on the heat, but only con- 

 sequentially, by evaporating the moisture, which they suppose returns again on 

 the bodies cooling. 



