distinction of kind or of sex, and whatever be the state of leanness, of fatness, of health and of disease, of these animals. 9th, The microscopic filaria, even when present in the approximate number of near 224,000, do not alter the instinctive faculties of the dogs, and do not at all weaken the muscular energy of these animals. 10th, The vermiferous blood of the dogs presents no very notable modifications in its physical characters, and in the proportionate weight of its organic and inorganic principles. 11th, The microscopic hematozoa transfused with from 150 to 300 grammes of a liqueur globuleuse defibrinæ into the vessels of nine dogs, whose blood contained no worms, disappeared from their blood in from the eighth to the fortieth day. The dogs were killed, and the filaria were neither found in the fluid secretions, nor in the tissues, nor in the different cavities. 12th, In two dogs, differing in kind and age, having no filaria in their blood, into whose vessels from 200 to 800 grammes of vermiferous defibrinised blood were ejected, the filaria have continued to live in the blood during more than three years, or up to their natural death. When opened and dissected these dogs have not presented any filaria save in their blood. 13th, The microscopic hematozoa of the blood of the dog transfused with the liqueur globuleuse defibrinæ into the vessels of two rabbits, have continued to live in the blood of one of them during eighty-nine days, after which time the filaria disappeared from the blood. At the autopsy of this rabbit the filaria were not found again in the tissues. 14th, The microscopic filaria transfused with the defibrinised liquor which we have mentioned into the blood of six adult frogs, two of which already had filaria in their blood, continued to live in the vital fluid of these animals during eight days, or during the time the globules of the dog's blood appeared unchanged among the globules of the frog's blood. On the ninth and tenth day, the globules of the dog's blood being altered, the microscopic filaria injected with it disappeared, and the eight frogs died of a scorbutic disease. These transfusions then demonstrate that the microscopic filarious blood cannot continue to live, either in the blood of the dog, or in that of other animals, save so long as that fluid possesses a constitution proper, and still unknown, to the maintenance of the life of these hematozoa. 15th, The filaria invisible to the naked eye injected alive, along with the blood which transports them along the vessels into the serous cavities, and the cellular tissue of healthy dogs, were unable to remain alive in these two new domiciles. 16th, A dog with vermiferous blood, with a female with blood not vermiferous, produces offspring, of which those belonging to the race of the father have vermiferous blood, while the others, pertaining to the race of the mother, have not. 17th, A vermiferous-blooded female dog, produced with a male dog without vermiferous blood, brings forth pups, of which those taking after the race of the mother have worms in their blood, while those resembling the father in race have none. 18th, A vermiferous-blooded female dog, with a male dog equally so, has pups with worms in their blood, whether these pups pertain to the race of the father or of the mother. 19th, The filaria in the blood of the pups have not been discovered before they have reached the age of from five to six months. The worms have continued to live in the blood of these animals, which have now reached the age of four or five years. 20th, Nineteen dogs, of which each had approximately from 11,000 to about 224,000 microscopic filaria in its blood, and also a dog having also in its blood six adult filaria, from fourteen to twenty centimetres in length, have never been seized with any special disease. Three dogs, however, having, approximately, the first 17,000, the second 25,000, and the third 112,000 microscopic filaria in the vital fluid, have been struck with epileptic-like attacks. Two of these animals died of the attacks; in the third the attacks have ceased. The health of this last dog has been perfect for more than a year, although the same number of worms always exists in the blood. Very numerous researches will yet be made on this interesting subject.* The author announces a new memoir on a strongylus which lives in the mesenteric arteries of the horse, and on the hematozoas, which live in the crow, the frog, and in many species of fish, and in the lumbricus terrestris or earth worm. Description of a Self-Acting Apparatus for preventing WaterPipes Bursting during Frost. By Mr ALEXANDER MACPHERSON, F.R.S.S.A., of Leith. Communicated by the Author. With a Plate. It is unnecessary for me to point to the highly-injurious consequences which often result from the bursting of water-pipes with frost; or to demonstrate the great necessity there exists for some proper and efficient remedy. With the exception, perhaps, of a serious fire, there is no agent more destructive in its effects upon property than an overflow of water. It is true that such an occur rence is frequently occasioned by the defective nature of the plumber-work; but there can be no doubt whatever, that the most prolific source of this kind of damage is due to the bursting of waterpipes with frost; and that is an event, it would seem, which the most skilfully-executed plumber-work can neither prevent nor resist. amount. The temperature in this country is rarely so low as to exhibit the consequences of a severe and protracted frost; and the cases of burst water-pipes have, therefore, been comparatively few. Since the winter of 1838–9, we have had no severe frost of any duration; but in that year, and others of equal severity, the water-pipes were burst all over the country, and this occasioned damage to a very large While this country, however, from its temperate climate, is, in a great measure, exempted from these effects of frost, it is different in countries where a colder temperature predominates. In the northern section of the United States and Canada, this freezing of the pipes assumes a much more formidable aspect. Many of the houses are warmed with furnaces placed in the cellars or halls; and I believe one of the chief objects of this expensive precaution, is that of preserving the water-pipes from freezing. There have been various attempts made to prevent the action of frost on water-pipes. Exterior protections of such non-conducting materials as charcoal, ropeyarn, straw, &c., have been applied to the exposed parts of the pipes, with the view of preserving the temperature. These, it is obvious, can afford but very slight protection in the event of an intense frost. It has been very generally recommended, also, as a useful precaution, to circulate the water through the pipes, by means of partially opening the cock at the sink. This, when it can be adopted with safety, is, to a certain extent, beneficial in preserving the supply-pipes from bursting; but it has been found extremely disadvantageous in freezing, and consequently obstructing, the soil-pipes and drains. From this cause, it is very often as in New York-prevented by the municipal authorities. The attempt, which I have frequently seen made, to resist the frost by means of strong pipes, is very absurd. No strength of pipes of any material can withstand the expansive force of water while frecz |