188 PHILOSOPHICAL TRANSACTIONS. [aNNO I765. 



of the moisture, which may leave the tinging corpuscles more dense, and some- 

 thing augmented by the accretion of the oily and earthy parts of that moisture." 

 Newton's Optics, lib. 1, prop. 7- This is the only passage in Newton, in 

 which he instances any permanent colour of a natural body as arising from a 

 change of density: and though he has not any where at large delivered his opi- 

 nion on this subject ; it appears that, in this case, he considered the less refran- 

 gible colours in withered vegetables as arising from their increase of density; 

 which is what I endeavoured in the beginning of this paper to prove deducible 

 from his doctrines. 



IV^. The Case of an Extraneous Body forced into the Lungs. By William 



Martin, Esq., of Shadwell. p. 39. 



On Tuesday Oct. 23, 1764, about 6 in the evening, as one of Mr. M.'s maid 

 servants was drinking coffee, and eating toast and butter, having a child in her 

 lap, who had like to have scalded itself, and she was apprehensive would have 

 broke the cup, being surprized, and attempting to speak hastily, in the very act 

 of deglutition, she unfortunately forced a piece of the crusty part under the epi- 

 o-lottis, which made its way into the larynx, or upper part of the wind-pipe ; and 

 notwithstanding the many efforts of nature by a violent and incessant cough, to 

 discharge it, yet it fixed like a wedge ; and in a few hours she was deprived of 

 her senses and her speech, and lay in great agonies, with violent agitations of 

 body, resembling strong convulsions, fetched her breath very short, and it was 

 expected she would expire that night. As Mr. M. was in the house when the 

 accident happened, every method that he could possibly think of was made use 

 of for her relief, but without effect ; and as respiration was attended with the 

 greatest difficulty, he ordered about 10 oz. of blood to be taken from her arm, 

 which seemed in some measure to relieve her breath ; this was 2 hours after the 

 accident. The cough continued about 3 hours, till her strength was in a manner 

 quite exhausted, and she seemed to be entirely senseless, except at intervals, 

 pointing to her breast ; and whenever Mr. Martin examined her pulse, forcibly, 

 and in great agonies pressing his hand to the scrobiculus cordis, as the seat 

 of her disorder. He left her about 12 o'clock that night; and desired his 

 servants who attended her, to call him, if they observed any sudden alteration, 

 which they accordingly did about 2 in the morning, when he was informed she 

 was expiring as they thought, and indeed he was of the same opinion. He 

 found her somewhat more sensible, but in great agonies; and making motions 

 to be blooded again ; as she had a full pulse, and the greatest difficulty in respi- 

 ration, he took away about the same quantity as before, which seemed to give 

 her some relief, and she continued much more quiet. At this time her cough 

 * had left her, and he was convinced by her complaints, that the extraneous body 



