488 PHILOSOPHICAL TRANSACTIONS. [aNNO I67O. 



duck's body, might either hasten her death by its being infected with them, or 

 hinder our discerning what should happen, by its being opacated by them. 



The bird being thus under water, began after a while, and from time to 

 time continued to emit divers bubbles at her beak. There also came out at her 

 nostrils divers real bubbles from time to time ; and when the animal had con- 

 tinued about two minutes or more under water, she began to struggle very 

 much, and to endeavour either to emerge or change her posture ; the lat- 

 ter of which she had liberty to do, but not the former. After four minutes, 

 the bubbles came much more sparingly from her : then also she began to gape 

 from time to time, but without emitting bubbles ; and so she continued gaping 

 till near the end of the sixth minute, at which time all her motions, some of 

 which were judged convulsive, and others that had been excited by our rousing 

 her with a forceps, appeared to cease, and her head to hang carelessly down, as 

 if she were quite dead. Notwithstanding which we thought fit, for greater se- 

 curity, to continue her under water a full minute longer, and then finding no 

 signs of life, we took her out and being hung by the heels, and gently pressed 

 in convenient places, she was made to void a pretty quantity of water, of 

 which whether any had been received into the lungs themselves, we had not 

 time and opportunity to examine. But all the means, that were used to re- 

 cover the bird to life, proving ineffectual, we concluded she had been dead a 

 full minute before we removed her out of the water : so that, to sum up the 

 event of our experiment, even this water-bird was not able to live in cold water, 

 without taking in fresh air, above six minutes ; which is but ^V of an hour. 



Exp. V. — The duckling mentioned in Exp. 2, Title I. having a competent 

 weight tied to her legs, was let down into a tub of water which reached not 

 above an inch or two higher than her beak : during the most part of her con- 

 tinuance, there came out a quantity of bubbles at her nostrils, but there seemed 

 to come out more and greater from a certain place in her head, almost equi- 

 distant from her eyes, but somewhat less remote from her neck than they. 

 Whilst she was kept in this condition, she seemed frequently to endeavour to 

 dive lower under water, and after much struggling and frequent gaping, she 

 had divers convulsive motions, and then let her head fall down backward, with 

 her throat upwards. To which motionless posture she was reduced at the end 

 of the third minute, if not a little sooner ; but a while after there appeared a 

 manifest but tremulous motion in the two parts of her bill, which continued 

 for some time, but afforded no circumstances whereby we could be sure that 

 they were not convulsive motions ; but these also ceasing upon the end of the 

 fourth minute, the bird was taken out and found irrecoverable. 



Exp. VI, — A viper that was kept so many hours in an exhausted receiver. 



