mortem appearances exhibited a paralyzed condition of the involuntary muscles; there was a distended bladder and an alternately dilated and contracted state of the intestines, especially of the colon, and the blood was black and uncoagulated. Mitscherlich in his cases found the blood red and firmly coagulated. With respect to the chemical inquiry, one or two points are worthy of notice, namely, that while the tissues were saturated with lead none could be detected in some of the secretions, as the urine and the bile; this will appear the more singular when we reflect that they are the two great channels by which effete and poisonous matters are eleminated from the system. Again, the presence of lead was recognised in the contents of the stomach, although none of the medicine had been given for two days. The coroner, in commenting upon this case, very properly censured the careless manner in which such a poisonous medicine had been dispensed; and observed that if another case of this kind were to fall under his notice he should consider it to be his duty to advise the jury in bringing in a verdict of " manslaughter." 10, Tredegar Square, Bow Road, November 15, 1845. VENTILATION OF COAL MINES. TO THE EDITOR OF THE PHARMACEUTICAL JOURNAL. SIR, PERMIT me to lay before your numerous and scientific readers, the following simple plan for the complete and perfect ventilation of coal mines; and to occupy as little of your valuable space as possible, I will now proceed to describe my plan. by first observing, that all the explosive gases are much lighter than the atmosphere, and consequently they ascend to, and are to be found in the roof and upper part of the mines: here they collect, and there not being any means adopted to carry off these explosive gasses, if through the want of caution on the part of the miner his light should be brought in contact with these gases, they immediately explode, dealing death and destruction to all around. All coal mines are worked by steam power, and to generate the steam it is necessary that there should be large furnace fires going night and day, and there are one, two, or three fires, according to the extent of the mines. First, The ash-pits to these furnaces should be inclosed by doors made air tight. At the bottom of the ash-pit and beneath the furnace let a barrel drain be dug, running from under the furnace to the mouth of the shaft, this drain being made under ground and well rammed with clay will make it air-tight down. to the shaft; connect to this barrel drain an iron pipe of the same size, let the iron main descend to the bottom of the shaft, then branch off to the several workings; suppose the iron main to be eighteen inches diameter, then of these several branchings, going in different directions, let each of these pipes be seven inches diameter. These pipes may be carried in the tramway to the furthest extent of the mine. Let these pipes have an elbow, and the pipe inserted be carried up above the roof of the mine, cutting a dome to allow all the foul air and expansive gases to accumulate. As soon as these connecting pipes are complete, and the passage of them rendered air-tight to the furnaces, the fires to support their own combustion will immediately draw off all the air, foul or not, which will be consumed by the fires; if there are any of the explosive gases they will assist to generate the steam. And as fast as these air-tight tubes or pipes exhaust the air in their immediate locality, so will fresh air rush down the shaft, and instantly take the place of the foul air that has been exhausted by the furnaces. This plan will effectually prevent any future explosion, by so working the roof of the mine that all the gases as they collect shall pass off to the dome, under which is the pipe constantly exhausting the air; but in cases where the furnaces are not continually burning, I propose placing in some convenient spot a large close furnace, constructed that it shall consume the refuse coal lying at the mouth of the shaft, in a state of spontaneous ignition, and consequently of no use. A branch barrel drain being carried from the furnace into and connected with the barrel drain from the other furnaces, so that this furnace will be performing the same office, namely, ventilating the mine, by burning the refuse coal, and keeping them in a constant state of ventilation. I am, Sir, your most obedient servant, Mineral Water Works, THE POTATO DISEASE. THE disease which has produced such extensive ravages among the potato crops, throughout a great part of Europe and North America, continues to occupy much of the public attention, to occasion serious anxiety and alarm, with regard to its probable effects during the approaching winter, and to form a subject for the investigations of the Naturalist and the analytical Chemist. Much diversity of opinion has been expressed by those who have written on the subject, both as to the probable origin or cause of the disease, and the best means of counteracting or providing against its effects. By some the disease is ascribed to the influence of a parasitic plant or fungus, the Botrytis infestans, which is said to be always found growing on the diseased plants. The spores of a species of fungus, called Uredo tuberosum, have also been found in the cells of diseased potatoes. Most observers have agreed in considering that the disease commences in the stem of the plant, and is propagated from thence to the tubers. The manner in which this propagation has been supposed to take place, is represented by the following wood-cuts, which are copied from a French publication : ارف The granules indicating on the stem the longitudinal fissures. The longitudinal fissures conveying the disease to the tubers. On the other hand, there are those who deny that fungi are aecessarily present where the disease exists. Among the advocates of this opinion is Mr. George Phillips, an excise Chemist, who has published a small pamphlet on the potato disease, containing the results of a microscopical and chemical examination of the healthy and affected plants. This author also denies that the disease commences in the stem of the plant; and says he has always found it first manifested in the tubers, and in those of the tubers which are deepest in the ground. have Professor Liebig says, "The researches I have undertaken upon the sound and diseased potatoes of the present year disclosed to me the remarkable fact, that they contain in the sap a considerable quantity of vegetable casein (cheese), precipitable by acids. This constituent I did not observe in my previous researches. It would thus appear that, from the influence of the weather, or, generally speaking, from atmospheric causes, a part of the vegetable albumen which prevails in the potato, has become converted into vegetable casein. The great instability of this last substance is well known, hence the facility with which the potato containing it undergoes putrefaction. Any injury to health from the use of these potatoes is out of the question, and nowhere in Germany has such an effect been observed. In the diseased potato no solanin can be discovered." A variety of methods have been suggested for preserving the sound tubers; for arresting the further progress of the disease in those that are but slightly affected; and for recovering at least some part that may be useful as food, from those that are most diseased. We have already published, in the October number of this journal, some suggestions on these points, emanating from a body of practical men, which have called forth the following communication from a correspondent : TO THE EDITOR OF THE PHARMACEUTICAL JOURNAL. SIR, I have noticed in the remarks contained in your journal of October, and in every communication I have elsewhere seen relative to the potato disease, that the whole of the nutriment of this vegetable is referred to the starch which it contains; great pains are therefore taken to instruct the public in the best method of separating it from the diseased portions, with the assurance that, by so doing, the whole of the nutritious matter is preserved. This to me appears erroneous. Our aliments are, from their chemical differences, arranged into two classes, azotized and nonazotized. In the latter are included the starches, sugars, and all bodies not containing nitrogen; and in the former, the various modifications of proteine, and those in which nitrogen forms an essential element. Each of these classes has its distinct duties to perform in the various functions of vitality: the nonazotized aliments are employed in those of respiration and the support of animal heat, and the azotized in the reproduction of those portions of our frames which are consumed by the incessant wear and tear to which they are subject by the processes of secretion and excretion. In the healthy potato both these conditions exist, the starch already admitted representing the nonazotized class, and an albuminous matter, exactly corresponding in chemical composition with the fibrine of the blood and tissues, belonging to the class of azotized bodies. It is this circumstance that renders this vegetable so eminently useful as an article of food, and enables many to depend almost entirely upon it for support; but if, as is the case, this albuminous portion be destroyed, or so altered as to become injurious, it is incorrect to ascribe to the residual starch, the double functions of the two classes. No doubt the separation of the healthy from the diseased part is greatly to be recommended, as under any circumstances it is better to lose a part than all, but the mere difference by weight thus experienced does not correctly state the loss as will certainly be proved to their sad disappointment by those who, depending on this as the main article of food, do also rely on this unfortunate assurance. I am, Sir, your very obedient Servant, 3, Regent Place, Clifton. October 26, 1845. GEORGE FREDERICK SCHACHT. Full and explicit instructions for preserving the sound or but slightly diseased potatoes, will be found in the subjoined address from the commissioners appointed by the government to investigate the state of the potato crops in Ireland. ADVICE CONCERNING THE POTATO CROP. TO THE FARMERS and TO THE PEASANTRY OF IRELAND. "THE dreadful disease that has attacked your potatoes, is one, the effects of which you can only stop by strict attention to the advice of those interested in your welfare. Many plans have been proposed, and after examining them all, we recommend the following as the best : "All competent persons are of opinion that the first things to bear in mind are the following directions : "1. Dig your potatoes in dry weather if you can, and if you cannot, get them dry somehow as fast as you can. 2. Keep them dry and cool. "3. Keep the bad potatoes separate from the good. “4. Do not pit your potatoes, as you have been accustomed to do in former years. "5. Recollect that if they get damp, nothing can make them keep; and do not consider them dry unless the mould which sticks to them is like dust. “6. Do not take them into your houses, unless you want them for immediate use. “Digging and Drying —As you dig the potatoes, leave them in the sun all day; and if you can, throw them upon straw, turning them over two or three times. At night you may gather them together and cover them with straw, so as to keep off frost. Next day take off the straw, spread them out, and give them the sun again. Do this for three days running, if the weather permit. If you put straw enough upon them at night, they will not suffer. "If the weather be unfavourable, and you have a dry loft or outhouse large enough to hold them, you may spread them thinly on the floor, allowing a free circulation of air, so as to dry them there. "They must be got dry. 66 Sorting the Potatoes. As soon as they are dry you must sort them. Pick them one by one, and put in one heap the very bad ones, in another those which are not so bad, and in a third those that are sound. Treat the bad potatoes as shall afterwards be directed, and store the sound ones according to the directions given in the next paragraph. You will know the very bad potatoes by their unpleasant smell, and the second set by their skin looking brown or dull, and not bright as it generally does; a very little practice will teach you how to distinguish them easily from each other. "Storing. When the potatoes are quite dry, and well sorted, proceed to store them thus :-Mark out on the ground a space six feet wide, and as long as you please. Dig a shallow trench two feet wide all round, and throw the mould upon the space, then level it and cover it over with a floor of turf-sods, set on their edges. On this, sift or spread, very thinly, the dry mixtures, or any of the dry materials described below, and which you may call packing stuff. Also, get some dry slacked lime, and dust all the potatoes with it as |