Page:The American Cyclopædia (1879) Volume II.djvu/761

 BLOODSTONE BLOOMARY 741 DIAMETER OF BLOOD COEPU3CLES IN MILLIMETRES. 0-0077 ...... 0-0074 ........ 0-0080 0-0070 ........ 0-0066 ........ 0-0074 ....... 0-0065 ........ 0-0060 ....... 0-0070 0-0060 0-0060 0058 0-0054 I.Man 2. Dog. 8. Kabbit 4. Eat 5. Pig 6. Mouse T. Ox 8. Cat 9. Horse 10. Sheep 0-0064 0-0062 ....... 0-0061 0-0058 0-0056 ........ 0-0053 0-0057 ........ 0-0058 0-0068 0-0065 0-0065 0-OU62 0-0060 0-0060 ........ 0-0044 ........ 0-0040 ........ 0-0048 Dr. Taylor says he has tried the method of Schmidt and has not found it practically avail- able, and he declares that the question of the distinction between the blood of man and that of certain animals is unsolved. He adds that when blood has been dried on clothing, we cannot with certainty and accuracy distinguish that of an ordinary domestic animal from that of man. Usually, however, in fresh blood, the measurement of the red corpuscles will decide the question; and in old stains, when the blood corpuscles have changed their form and become jagged or stellate, it will often occur that sev- eral substances will give them their normal shape and render possible the determination of their source. But the evidence here is based on conjecture only, and should therefore be re- ceived with the greatest caution. Not only can the red corpuscles be altered in their size and shape, but they may be decomposed and give origin to crystals which are so similar, whether coming from the blood of certain animals or that of man, that no distinction is possible. Fortunately there are almost always at least a few undecomposed red corpuscles among the crystals. III. It is absolutely impossible to distinguish the blood of one man from that of another by means of the comparison of the red corpuscles. There may be more difference be- tween the corpuscles of two samples of blood from the same man than between those of two men. A great many external causes may pro- duce variations in the size of the red globules; and besides, the proportion of water and of certain gases or salts in the blood has a great influence on the shape and dimensions of the red corpuscles. All who know the facts ad- vanced in favor of or against the theory of Henle, concerning the causes of the difference of color of the arterial and venous blood (see RESPIRATION), are aware of the changes of the blood corpuscles due to oxygen, carbonic acid, &c. The smell of the blood of women might by some persons be distinguished from that of the blood of men, but we cannot place any re- liance on the senses of anybody for such a dis- tinction ; and we know that even Barruel, who discovered the influence of sulphuric acid in increasing the odor of blood, once failed to dis- tinguish the blood of a man from that of a woman. Chemistry also is of no avail for the discrimination of the blood of one man from that of another. BLOODSTONE, a variety of quartz, of a dark green color, having little red spots of jasper sprinkled through its mass. When cut and polished, the red spots appear like little drops of blood. It is somewhat prized as a gem. BLOOMARY, a name sometimes given to a kind of furnace for the production of malleable iron from cast or pig iron, and sometimes to a similar furnace for the direct extraction of mal- leable iron from its ores. In both cases the lump of iron obtained, when finished under the hammer, is called a bloom, from the German Blume, a flower, because, it is said, the product is as it were the flower of the 6re. The direct fabrication of malleable iron from the ore ap- pears to have been practised from remote anti- quity. The natives of India, Burmah, Borneo, Madagascar, and some parts of Africa practise the direct conversion of iron ores into metallic iron in furnaces which are rude bloomaries. In certain districts of India the amount of me- tallic iron thus produced is very considerable, and much of it is manufactured into steel ; but the furnaces used are small in size and do not yield more than 30 or 40 Ibs. of iron daily, with the labor of three or four men, and a great waste of ore and charcoal. The massive rich ore coarsely pulverized, or the grains of iron ore obtained by washing the sands in some places, are heated with charcoal in shallow open furnaces until reduced to the metallic state ; but as the metal thus produced is infusi- ble at the heat of these furnaces, it agglutinates into an irregular mass, known as a loup, which is afterward hammered and converted into a bloom. Somewhat similar methods of making malleable iron have long been known in various countries of Europe, where under improved forms they are still followed, and have thence been brought to North America. Of these furnaces for the direct production of blooms from the ore five forms are known in Europe, viz. : the Corsican and Catalan forges, the German bloomary forge, the Osmund furnace, and the German Stucleofen or high bloomary furnace, which had high walls and approached in form the modern blast furnace, of which it seems to have been the immediate precursor. All of these employ a blast to increase the heat, but the name of blast furnace is technically given only to those furnaces in which by in- creasing the heat the reduced iron is subse- quently carburetted and fused, being thus sep- arated in the 'form of cast or pig metal from the melted impurities or slag, both of which are drawn off by tapping the furnace from time to time. The production of iron in this way is a continuous process, while in the various bloomary furnaces the operation is interrupted from time to time In order to remove from the hearth the accumulated mass of reduced but unmelted malleable iron, which is then freed from the slag or cinder by hammering. Of these furnaces the Corsican is the most primi- tive form, and is now nearly if not quite dis- used. It was said to consume more than 800 Ibs. of charcoal in making 100 Ibs. of iron. The Catalan forge or bloomary is so called from the province of Catalonia In Spain, where it was