the medulla spinalis in the neck, by coagulated blood, produced paralytic affections of the arms and legs, all the functions of the internal organs were carried on for thirty-five days, but the urine and stools passed involuntarily.

Blood extravasated in the central part of the medulla in the neck, was attended with paralytic affection of the legs, but not of the arms.

In a case where the substance of the medulla was lacerated in the neck, there was paralysis in all the parts below the laceration; the lining of the œsophagus was so sensible, that solids could not be swallowed, on account of the pain they occasioned.

Where the medulla in the back was completely divided, there was momentary loss of sight, loss of memory for fifteen minutes, and permanent insensibility in all the lower parts of the body. The skin above the division of the spinal marrow perspired, that below did not. The wounded spinal marrow appeared to be extremely sensible.

Extract of a Report, presented to the French Institute on the 26th of Frimaire, in the year XIII. by Messrs. Guyton Morveau and Chaptal, on the Question whether the Manufactures which exhale a disagreeable odour can be injurious to health. Translated for the Eclectic Repertory, from the Bulletin of the Society for the Encouragement of National Industry. No. 116. February, 1814.

This important question, on which the minister of the interior consulted the first class of the Institute, essentially affects the prosperity of our manufactures. In order to effect a satisfactory solution, the committee have deemed it their duty to take a general view of the arts to which the strongest objections have been made. They have divided them into two classes: the first, comprehending all the arts, the operations of which discharge into the atmosphere, as the consequence of putrefaction or fermentation, certain gaseous emanations, which may be considered as disagreeable in smell, or dangerous in effect; such as the rotting flax and hemp, the making of

catgut, and starch, slaughter-houses, tan-yards, breweries, &c. The second class comprehends all those in which the artist, operating by the action of fire, disengages in the form of vapour or gas, various principles, which are more or less disagreeable to respiration, and which are reputed more or less injurious to health. In this class may be included the distillation of acids, of spirits, of animal matter, the gilding on metal, the preparations of lead, copper, mercury, &c.

The arts comprehended in the first class, in relation to the health of the community, deserve particular attention; because the emanations disengaged by fermentation and putrefaction, are really injurious to health in some cases and under particular circumstances. For instance, the process of rotting, carried on in stagnant waters or pools, infects the air and destroys the fish: the diseases occasioned by it are well known and described; hence wholesome regulations have directed in most places, that this operation should be conducted beyond the limits of the towns at a certain distance from every habitation; and in waters the fish of which do not constitute the food of the people.

The other operations performed on vegetables, or on certain products of vegetation, for obtaining fermented liquors, as in breweries, for extracting colours, as in the manufacture of turnsole, alga tinctoria, and indigo, or for depriving them of certain principles, as in the making of starch, paper, &c. are not of a character to excite any solicitude on the part of the magistrate. In all instances, the emanations arising from these articles in the state of fermentation, can only prove dangerous immediately near the vessels or apparatus; they cease to be so when mixed with the external air; hence a little precaution will obviate all danger. Moreover there is no danger to the inhabitants in the neighbourhood; the persons engaged in the works can alone be affected; accordingly, any regulations directing the removal of such works out of the towns, and at a distance from any dwellings, would prove at once unjust, vexatious, and ruinous to the arts, without remedying the evil incidental to their operations.

Some preparations extracted from animal substances often require the putrefaction of these substances, as in the making VOE. V. No. 20.

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of catgut; but more frequently the substances are liable to become putrid, by remaining too long in the factory, or by being exposed to too great a heat. This is particularly observable in dyeing cotton red, in which a large quantity of blood is employed. The effluvia exhaled from these putrid articles, extend to a great distance, and form, in the neighbourhood, an atmosphere very disagreeable to respiration. It is the duty of the police, to cause these substances to be frequently renewed, so as to prevent putrefaction, and to direct the observance of sufficient cleanliness in the factories, so that no putrid filth shall be collected from the animal substances which have been employed.

On this account, slaughter-houses may be considered nuisances, but not such as to require their being removed out of town, or collected in one place. A little attention on the part of the magistrate, so that butchers shall not throw out the blood and the offals of the animals they have killed, will fully prevent every thing offensive or unwholesome which the slaughterhouses might occasion.

The conversion of human ordure into a powder has been lately introduced in all the large towns of France; the process necessarily occasions, for a length of time, the evolution of a very disagreeable odour. Such establishments ought therefore to be formed in very airy situations and at a distance from all habitations.

A very important observation here presents on the spontaneous decomposition of animal substances; it is, that the emanations appear to be less dangerous in proportion as the articles which undergo putrefaction are less humid. In this case, a considerable quantity of carbonated ammonia is disengaged, imparting its predominant character to the volatilized matters, and correcting the bad effects, which might be dele

terious.

Thus the decomposition of stercoraceous matter in the open air, and in situations where the inclination of the ground allows the fluids to run off, the decomposition of the remains of the cocoons of the silk worm, evolve an enormous quantity of carbonated ammonia, while the same substances immersed in water, or moistened with this fluid, exhale miasmata, faint, nauseous and dangerous to respiration.

The numerous arts in which the manufacturer produces and diffuses in the air, by the aid of fire, and as the consequence of his operations, vapours more or less disagreeable to respiration, constitute the second class of those remaining to be examined.

These are more interesting than the first, and much more intimately connected with the prosperity of national industry, and more frequently the subjects of indictments brought before the magistrate; and on this account, they merit a more particular attention.

The acids, the preparation of which may excite some complaints on the part of those living in the neighbourhood of the laboratory, are the sulphuric, the nitric, the muriatic, and

acetous.

The sulphuric is obtained by the combustion of a mixture of sulphur and saltpetre. In this operation it is difficult to prevent an odour, more or less marked, of sulphurous acid, from being diffused round the apparatus where the combustion is carried on; but where the process is skilfully conducted, this odour is scarcely perceptible in the laboratory; it causes no danger to the workmen, who breathe it daily, and no complaint on the part of the neighbours can be well founded. When the manufacturing of sulphuric acid was introduced in France, the public opinion was strongly expressed against the first establishments. The odour produced by the burning of matches in our kitchens contributed not a little to magnify the effect that would be produced by the rapid combustion of some hundred weights of sulphur. At present these prejudices have subsided; and in the very hearts of our towns these manufactories are observed to flourish without the slightest inconvenience or molestation.

The distillation of nitric and muriatic acids occasions no more danger than the making of sulphuric acid. The whole operation is performed in vessels of glass, or stone ware; and it is unquestionably the interest of the manufacturer to diminish, as much as possible, the loss or volatilization. Notwithstanding every attention in the process, the air of the laboratory will be impregnated with the particular odour of each of these acids; nevertheless respiration is free, and perfectly safe.

The men who are constantly engaged in the works, are not incommoded, and the neighbours can have no right to complain.

Since the manufactories of white lead, verdigris, and the sugar of lead have been multiplied in France, vinegar has been more extensively employed.

When this acid is distilled to adapt it to some of these purposes, a very strong smell of vinegar is widely diffused, but unaccompanied by danger: when, however, a solution of lead in this acid is evaporated, the vapours partake of a sweetish character, and produce, on the persons who habitually breathe them, all the peculiar effects occasioned by the fumes of lead itself. Happily these effects are confined to the workmen engaged in the laboratories, and do not extend to the persons who live in the neighbourhood.

The preparations of mercury and lead, and those of copper, antimony, and arsenic, the process of gilding on metal, are all fraught with some danger to the persons inhabiting the laboratories, or assisting in the operations; but the effects are confined to the limits of the building; the workmen and manufacturers are alone exposed to any risk or danger. The means of preventing these ill effects are worth the attention of chemists, many of the inconveniences have been already obviated by the construction of flues, which conduct the vapours beyond the sphere of respiration; and, at present, the attention of the administration might be confined to directing science in the means of perfecting the processes, as far as they are susceptible, in regard to health.

The formation of Prussian blue, the extraction of the carbonate of ammonia by the distillation of animal substances in the new manufactories of sal ammoniac, produce a great quantity of fœtid vapours or exhalations: indeed these exhalations are not dangerous to health; yet, the proprietors of these establishments, when looking out for a situation, ought to prefer one at a distance from any habitation. But when the establishment is already formed, it will be sufficient if the proprietors are required to construct very high chimnies so as to dilute the disagreeable vapours produced in these operations. This mean is particularly practicable for Prussian blue.

Though the committee of the institute confined their atten