76 



1. The Antiar is a paralysing poison. 



2. It acts in the first instance and with great rapidity (in 5 to 

 10 minutes) upon the heart, and stops its action. 



3. The consequences of this paralysis of the heart are the cessa- 

 tion of the voluntary and reflex movements in the first and second 

 hour after the introduction of the poison. 



4. The Antiar paralyses in the second place the voluntary 

 muscles. 



5. In the third place it causes the loss of excitability of the great 

 nervous trunks. 



6. The heart and muscles of frogs poisoned with Urari may be 

 paralysed by Antiar. 



7. From all this it may be deduced, that the Antiar principally 

 acts upon the muscular fibre and causes paralysis of it. 



So much for this time. My experiments with the Antiar upon 

 warm-blooded animals have only begun, and I am not yet able to 

 draw any conclusion from them. As soon as this will be possible, I 

 shall take the liberty to submit them to the Royal Society, together 

 with the results of my experiments with the Upas tieute, which 

 poison I had also the good fortune to obtain through the kindness of 

 Sir Benjamin Brodie and Dr. Horsfield. With regard to the Antiar 

 I may further add, that experiments made independently, and at 

 the same time, by my friend Dr. Sharpey with this poison, have con- 

 ducted to the same results as my own. 



II. " On some Physical Properties of Ice." By JOHN TYNDALL, 

 Ph.D., F.R.S. Received December 17, 1857. 



(Abstract.) 



In this paper the following points are considered : 



1 . The effects of radiant heat upon ice. 



2. The effects of conducted heat upon ice. 



3. The air- and water- cavities of ice. 



4. The effects of pressure upon ice. 



For the experiments on radiant heat, slabs of Wenharn Lake and 

 Norway ice were made use of. Through these a solar beam, con- 



