270 ANNUAL OF SCIENTIFIC DISCOVERT. 



because there may have been an oversight in the popular opinion, re- 

 specting the beneficial effect of well-ventilated dormitories, we are not 

 to conclude that ventilation even in dormitories is useless. Far from 

 it. The question is a question of degree. That amount of fresh air 

 which permits prolonged sleep is the standard we must aim at, but bet- 

 ter to have impure air than cold." Cornliill Magazine. 



WHY ANIMALS TO BE EATEN MUST BE KILLED. 



It is universally understood that animals which die from disease are 

 not fitted for our markets. It is also understood, that when cattle have 

 been over-driven, their meat is notably inferior to that of healthy ani- 

 mals, unless they are permitted to recover their exhausted energies 

 before being slaughtered. Why is this ? The first and most natural 

 supposition respecting those which die from disease is that their flesh 

 is tainted ; but it has been found that prolonged agony or exhaustion 

 is quite as injurious, though in these cases there is no taint of disease. 

 M. Claude Bernard propounds the following explanation : In all 

 healthy animals, no matter to what class they belong, or on what food 

 they subsist, he finds a peculiar substance, analogous to vegetable starch, 

 existing in their tissues, and especially in their liver. This substance 

 he calls glycogene, i. e. the sugar-former. It is abundant in proportion 

 to the vigor and youth of the animal, and disappears entirely under 

 the prolonged suffering of pain or disease. This disappearance is sin- 

 gularly rapid in fish ; and is always observed in the spontaneous death 

 of animals. But Avhen the death is sudden none of it disappears. He 

 finds that a rabbit, for example, which is killed after suffering pain for five 

 or six hours, exhibits no trace whatever of this sugar-forming substance ; 

 and its flesh has a marked difference in flavor. The same remark ap- 

 plies to exhausted over-driven animals ; their muscles are nearly de- 

 ficient in ylycogene, and yield in water a far larger proportion of solu- 

 ble principles than the same muscles in a normal condition. M. Ber- 

 nard finds, moreover, that animals which are suffocated lose more of 

 the sugar-forming substance than similar animals killed in the 

 slauo-hter-house. To this let us add the fact, that the blood of over- 



^j 



driven animals will not coagulate, or coagulates very slowly and im- 

 perfectly ; and we shall see good reason for exercising some circum- 

 spection over the practices of our meat markets. 



CHANGES IN THE HABITS OF FISH. 



At a recent meeting of the Boston Society of Natural History, Capt. 

 Atwood, of Provincetown, Mass., gave an account of the changes the 

 fisheries of the New England coast had undergone ; and of the varia- 

 ble habits of many species of fish. Early accounts state, that up to 

 17G4, blue-fish (Tennodon saltator Cuv.) were very common north of 

 Cape Cod ; after which date they disappeared. Having had an ex- 

 perience of forty years in connection with the fisheries, he could say 

 that none had been seen north of Cape Cod, until twenty-five years 

 ago, when he saw his first blue-fish. Those found at that time were 

 invariably small, the largest weighing about two pounds. In 1839, they 

 were caught off Nantucket, weighing eight to ten pounds ; in two or 

 three years more those coming north of Cape Cod were larger, and 

 drove away the mackerel and smaller fishes, and completely filled 



