970 EXPERIMENTS OF HERING, BLAKE, 



when applied to the tongue, than to the intes- 

 tines, and sooner in small than large animals. 



Muller relates, thatHering found from eighteen 

 experiments on horses, that ferrocyanate of pot- 

 ash mixed with the blood passed from one jugular 

 vein, through the lungs and general system to the 

 opposite jugular vein, in from 25 to 30 seconds, 

 from the jugular vein to the great saphena in 20 

 seconds, from the jugular to the masseteric 

 artery in from 15 to 30 seconds, to the facial 

 artery in one experiment in from 10 to 15 seconds, 

 and from the jugular vein to the metatarsal 

 artery in from 20 to 30 seconds. Muller also 

 states from his own experiments, that coloured 

 fluids pass through living membranes in one 

 second, so as to be seen on the opposite side ; and 

 he thinks that the speedy effects of hydrocyanic 

 acid are owing partly to its elasticity, by which it 

 is rapidly diffused, absorbed into the circulation, 

 and thus conveyed to the brain and spinal mar- 

 row. 



Mr. Blake has further shown, in a paper pub- 

 lished in the Med. and Surg. Journal, vol. 53, 

 and another in the Lond. Med. Gazette of June 

 18, 1841, that the rapidity with which poisons 

 operate is in proportion to the activity of the 

 circulation, and the nearness of their application 

 to the nervous centres : that hydrocyanic acid 

 never produces its first symptoms sooner than 9 

 seconds : that one grain of strychnia dissolved 

 in a small quantity of acetic acid, produced con- 



