MUCUS. 



483 



From the descriptions which I have now 

 given I think it will be a'lowed that, inasmuch 

 as the mucus which is obtained by the chemical 

 analysis of different secretions fails to show, 

 when subjected to tests, those agreements in 

 reaction which must be regarded as essential 

 to prove identity, the question as to the 

 existence of any substance to which the name 

 of " mucus" should be applied, as one of the 

 proximate elementary animal bodies, should 

 be regarded as concluded. That there is 

 always a matter present in the secretions of 

 mucous membranes, which possesses a gluti- 

 nous character, and to which the physical 

 properties of the secretion are owing, is un- 

 doubtedly true; but this is quite a distinct 

 question from whether or not this tenacious 

 constituent be entitled to the rank of a proxi- 

 mate element : and the fact of a difference 

 being observed in the chemical reactions of 

 this body, as obtained from various secretions, 

 strongly opposes such an idea. In order to 

 examine into this question I made, some time 

 ago, at the suggestion of Dr. Bright, some 

 chemical observations on those effused fluids 

 which partake more or less of the mucous 



character,* such as the effusions which occur 

 in ovarian dropsy, and to compare the results 

 obtained with similarly conducted experiments 

 on other fluids of a more purely serous character, 

 and also with serum of blood, as it appeared 

 probable that some point of difference might be 

 detected to which the mucoid character could 

 be traced, notwithstanding the total absence of 

 any substance obtainable in a solid form and ex- 

 hibiting physical characters like those of mucus. 

 I subjoin the examination of five fluids effused 

 in ovarian tumours, and one of a purely serous 

 character drawn from a case of ascites ; the serum 

 of blood is also offered for comparison ; the 

 separation of these fluids being carried only 

 so far as the division into free albumen, 

 aqueous extractive, and alcoholic extractive. 

 These analyses were made on equal weights, 

 or nearly so, of solid matters, obtained by 

 evaporating each fluid, as previous observation 

 had convinced me that the viscous character 

 into the nature of which I was examining 

 was quite independent of the degree of con- 

 centration of the effusions, the most tenacious 

 generally possessing the lowest specific gravity. 



Albumen 



Aqueous extractive . . 

 Alcoholic extractive. 



These analyses at once showed that the 

 aqueous extractive existed in greater proportion 

 in the tenacious fluids of ovarian cysts than 

 in the more serous effusion of ascites and 

 the serum of blood ; but another difficulty 

 remained to be solved, which was, that some 

 of these viscous liquors which were less mucoid 

 in character than others, did not indicate the 

 cause of such difference when the examination 

 had been extended only to the separation into 

 the three parts above mentioned, viz. albumen, 

 aqueous extractive, and alcoholic extractive. 

 On incinerating the aqueous extractive, how- 

 ever, so as to ascertain the proportion of 

 animal matter and alkaline salts contained in 

 it, 1 discovered that, while those specimens 

 which showed the mucoid character in a more 

 marked degree contained salts and animal 

 matter in nearly equal proportions in their 

 aqueous extractive, those in which the mucoid 

 character did not greatly predominate either 

 showed a deficiency or excess of salts ; both 

 conditions appearing more or less to interfere 

 with the perfect development of the peculiar 

 tenacious character of the secretion. I have 

 now to notice the late ingenious and valuable 

 observations of Dr. Babington, who has done 

 more to assist this inquiry than any observer 

 who has as yet examined into the subject. 

 In a paper published in the fifth number of 

 the Guy's Hospital Reports, Dr. Babington de- 

 scribed some experiments showing that various 

 albuminous matters were capable of assuming 

 the mucous character by mixture with the 

 alkalies. Serum of blood, pus, milk, and 

 white of egg were all so affected ; and the 



glairy mass so obtained was insoluble in water, 

 precipitable by diacetate of lead, but not by 

 bichloride of mercury or infusion of galls. 

 It admitted of being washed with water till 

 all traces of alkalinity were removed, but it 

 still retained its mucous character. This syn- 

 thetical formation of mucus is a most important 

 fact ; and I see no reason whatever to doubt 

 that the artificially formed viscous mass differs 

 from that secreted by membrane. It is true 

 that the latter always contains microscopic 

 globules, which of course are wanting in the 

 artificial product; but these globules are, I 

 believe, in no way connected with the viscous 

 character of mucus, but are rather superadded 

 to it, and frequently in very small proportion 

 to the mass of the secretion. 



The experiment of Hunter, who consolidated 

 albumen by the addition of hydrochlorate of 

 ammonia, as also the observations of Dr. Pearson 

 on the action of some others of the neutral 

 salts on pus, are confirmed by Dr. Babington 

 in the paper to which I have alluded. The 

 microscopic history of mucus, or rather of 

 those organic globules which accompany the 

 secretion, is a matter of considerable interest: 

 before entering upon it, however, I wish to state 

 my reasons why these globules are not, according 

 to my belief, the cause of the viscous character 

 of mucus. In the first place we do not 

 observe them in sufficient numbers to autho- 

 rize such an opinion ; and, secondly, some of 

 the most viscous forms of the secretion do 

 not become corrugated to any perceptible 



* See Guy's HospiUil Reports, April 1833. 



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