OP ABSORPTION. ^Q 



rate of lime : he Introduced into another portion some hydrochloric acid and surrou nd - 

 ed it with sulphuric acid ; finally, he placed a bladder, filled with tincture of turnsol, 

 in a solution of gall nuts. Sometime afterwards he found in the interior of these por- 

 tions of the intestine and of the bladder, hydrochlorate of lime, sulphuric acid, and gal- 

 lic acid, by the tests of nitrate of silver, hydrochlorate of barytes, and sulphate of iron; 

 and in the' liquids in which they had been immersed, prussiate of potass, hydrochloric 

 acid, and tincture of turnsol, by the tests of sulphate of copper, the nitrate of silver, and 

 by the reddish colour of the solution of galls being rendered bluish by the potas.s. 



On injecting at the same time into the pulmonary vein of a sheep, a solution of hy- 

 drochlorate of barytes, and one of the hydrocyanate of potass into the trachea, Fo- 

 dera also found hydrocynute of potass in the pulmonary artery, and hydrochlorate of 

 barytes in the bronchia:. 



Similar phenomena may be produced upon a living animal, Fodera has found, for 

 example, in the bladder or in the thorax, substances which had been injected into the 

 peritoneum ; and in the abdominal cavity, substances which had been introduced into 

 the thorax or bladder. In these experiments he employed the solution of gall and sul- 

 phate of iron, or rather, the latter salt and prussiate of potass. 



The black or blue colour, announcing that transudation has taken place, is frequently 

 not observed until the end of more than an hour : it may be rendered almost instantane- 

 ous by putting in action the galvanic influence. For this purpose, this ingenious expe- 

 rimenter injects into the bladder, or into a portion of the intestine of a living rabbit, a 

 solution of prussiate of potass, communicating with a copper wire ; externally, he places 

 a cloth wet with a solution of the sulphate, communicating with an iron wire : these 

 wires are put in contact with those of the pile. If the galvanic stream be directed from 

 the exterior to the interior,. by making a communication between the iron wire and the 

 positive pole, and between that of copper and the negative, the tissues of the organs im- 

 bibe the Prussian blue : if the stream be changed, the colour appears on the cloth. 



M. Fodera injected into the left cavity of the thorax of a rabbit a solution of hydrocy- 

 anate of potass, and into the peritoneum a solution of sulphate of iron ; he afterwards 

 kept the animal placed on its left side for three quarters of an hour. At the end of this 

 period the animal was opened, when he found that the whole of the tendinous part of 

 the diaphragm had imbibed the blue matter; the muscular part was much less tinged, 

 and only in isolated points. The substernal lymphatic glands were likewise blue. 

 The thoracic duct contained a bluish liquid : the peritoneal membrane of the stomach, 

 and duodenum was coloured with spots of the same colour : they were observable, but 

 in less number, on the rest of the digestive canal and on the arteries. The lymphatic 

 glands of the mesentery, the suspensory ligament of the liver, the epiploon, were also 

 tinged blue. Some small subperitoneal veins presented a slight blue colouration of the 

 liquid contained in their interior. Twelve hours afterwards, the blue tint of these dif- 

 ferent parts was much more intense. 



The progress of the colouration may be traced, and the phenomenon in some measure 

 be seen in its different phases t by injecting a femiretted solution of prussiate of potass 

 into a portion of the intestine of a living animal ; tying both ends, and plunging it into 

 a bath containing sulphate of iron. At first a slight coloration, only, is observable in the 

 parts, which gradually becomes deeper : afterwards the liquids of the lymphatics and 

 of the blood-vessels become coloured in turn. In these latter, the coloration begins 

 by small ramifications, and afterwards extends to the branches, which are observed to 

 be tilled with intervals of blood and a blue liquid. In these experiments Fodera 

 discovered the presence of the prussiate of iron in the lymphatic vessels, in the thoracic 

 duct, and, finally, in the portion of the inferior vena cava contained in the chests. 



Mr. Fodera concludes, from these different experiments, 1st, that exhalation and ab- 

 sorption take place by transudation and imbibition, and depend on the capillarity of the 

 tissues ; 2dly, that th'is double phenomenon may take place in every part, and that the 

 liquids imbibed may be conveyed equally well, either by the lymphatic vessels, or by 

 the arterial or venous. But (the author very wisely adds) the phenomena of exhalation 

 and absorption ought not to be considered as connected alone with imbibition and tran- 

 sudation : the modifications which they experience from the action of surrounding- 

 agents, from the nervous influence, the state of rest and motion, the energy of the cir- 

 culation, the affinities of the substances with the tissues, the derangements produced by 

 disease, and the elaboration which the fluids undergo whilst absorption and exhalation 

 are taking place, ought likewise to be studied. 



Mr. Fodera endeavours to explain the increase of exhalation in the phlegmasiae by 

 the dilatation which the parietes of the capillary vessels experience ; the interstices of 

 the fibres which form these parietes become at such times increased, and, consquently, 

 permit a more ready issue to the fluids : the serosity and the white globules, which are 



