306 ANNUAL OF SCIENTIFIC DISCOVERY. 



active agents in this series of creations, effectually aiding in the 

 formation and regeneration of the tissues. 



The results of the experiments of these authors are important, 

 and furnish new and much desired materials for the stud}^ of cel- 

 lular physiology. 



RATTLESNAKE POISON. 



From experiments on pigeons, Dr. Weir ^litchell has arrived at 

 the following conclusions: The venom of the rattlesnake is per- 

 fectly harmless when swallowed, as it cannot pass through the 

 mucous surfaces, and unders^oes a change during digestion which 

 allows it to enter the blood as a harmless substance, or to escape 

 from the canal in an equally innocent form. Twenty-four hours 

 after it lias been svvallowed, the contents of the bowel contain no 

 poison. The rectum does not absorb the poison, and it causes no 

 injury when placed in contact with the conjunctiva. It passes 

 throujrh the membranes of the brain, and more swiftlv through 

 the peritoneum and pericardium ; when it passes through the per- 

 itoneum, it so affects the walls of the capillaries as to allow of 

 their rupture and of the consequent escape of blood. The same 

 phenomena appear on the bare surface of muscles thus poisoned, 

 which, together with the defect of the coagulability of the poisoned 

 blood, account for the excessive bleeding about the fang wounds. 

 The blood globules are unaltered. The animal is not susceptible 

 of injury by the venom of its own species. 



The sulphites or hyposulphites of soda or lime have no antidotal 

 power. Carbolic acid sometimes delays the fatal result, and usu- 

 ally lessens local bleeding, from no influence of the acid on the 

 venom, but from a dii-ect effect upon the local circulation of the 

 poisoned part ; it has no value as a true antidote, and when given 

 internally does not affect the ordinary fatal issue. — N. Y. Medical 

 Journal. 



MINUTE PARTICLES IN THE AIR OF CITIES. 



Mr. J. B. Dancer found the following objects in the air of Man- 

 chester, England. Spores appeared in immense numbers, 250.000 

 to every drop of the water containing the air washing, varying 

 from one ten-thousandth to one fifty-thousandth of an inch in di- 

 ameter; their peculiar molecular motion was observable for a 

 short time. The mvcelium of these minute fungi was similar to 

 that of rust or mildew, such as is found on straw and decaying 

 vegetation. In 36 hours the fungi had greatly increased, and on 

 the third day a number of ciliated zoospores were seen moving 

 freely among the spores. 



The next in quantity was vegetable tissue, the greater portion 

 under high powers, exhibiting what is called the pitted structure; 

 many particles were evidently partially burnt wood used in light- 

 ing fires. Along with these were fragments resembling hay and 



