I860.] Physiology. 179 



neutral oxygen does not combine with the carbon of the blood unless 

 it is diluted. The death of animals in pure oxygen is not by a nar- 

 cotic poison, but by a process of negation. By a dilution of the 

 blood to the specific gravity of 1,060 the absorption of oxygen is 

 increased to a maximum ; when further diluted, the absorption de- 

 clines. Fresh oxygen prepared from chlorate of potassa increases the 

 activity of the functions ; but if exposed to ammonia, decomposing 

 animal matter or even living animals, it loses its activity, and no 

 longer combines with the blood. Alcohol, chloroform, opium, and 

 certain alkaline products formed in the blood in disease prevented ab- 

 sorption of oxygen, and death not uncommonly took place from this 

 cause. 



The same physiologist communicated a paper " On the Physiologi- 

 cal Effects of Tobacco," in which the composition of the products of 

 combustion of tobacco, their physiological action on the body, and the 

 effects of ordinary and excessive smoking were considered. The 

 paper was full of detail, so that to furnish an intelligible abstract in 

 a brief space is difficult. The author concluded by saying, that in the 

 main, smoking is a luxury which any man is better without, but of 

 nearly every luxury, tobacco is the least injurious. It is innocuous 

 as compared with alcohol ; it does infinitely less harm than opium ; 

 it is in no sense worse than tea ; and, by the side of high living, alto- 

 gether contrasts most favourably. 



In an elaborate report " On the Physiological Action of the Nitrite 

 of Amyle," Dr. Richardson pointed out the various effects which he 

 had observed it to produce upon the animal body, amongst the most 

 remarkable of which, we may especially refer to the violent action it 

 induces in the heart, with dilatation of the capillaries, followed by 

 diminished power of the heart and contraction of the extreme 

 vessels. It possesses the power of so reducing the respiration and cir- 

 culation, that a state precisely analogous to trance or catalepsy is 

 induced. It is not an anaesthetic. 



Various papers were read by Dr. Cobbold on meat, vegetables, 

 fruits, and water, as sources of Entozoa. He described the various 

 species of entozoa found in the flesh of animals used as food ; he 

 referred to the difficulty often experienced in detecting them, and 

 stated, that eating raw or half-cooked meat, was a frequent means of 

 introducing parasites into the human body, all danger of injury to man 

 being avoided when a proper temperature is employed in cooking. 

 From the fact of vegetables harbouring various small molluscs, the ova 

 of entozoa may be introduced into the system, for multitudes of small 

 parasites are not unfrequently contained in these molluscs. The more 

 filthy the water or liquid manure employed to secure the fertility of 

 the garden the more likely were the vegetables to harbour entozoa. 

 The most careful washing was therefore necessary, and even soaking 

 vegetables in brine before cooking might at times be advisable. Fruit, 

 as far as the author knew, was never a source of entozoa. Fresh 

 spring water was perfectly innocuous, but water stored in tanks often 

 contained parasites and their ova. Drinking water into which the 



