SCIENCE. 



621 



chemical powers of attraction, as we have clone in the pre- 

 ceding discussions. The question may now be raised, 

 how large a fraction of the whole combustion takes place 

 in the muscles, and how large a fraction in the other parts 

 of the body ? The distribution of the process of combus- 

 tion in the different places might, therefore, be accom- 

 plished in two ways. One part of the material might be 

 consumed entirely in the muscles, the other entirely else- 

 where, or certain stages of the combustion of the whole 

 material might take place in the muscles, and other stages 

 in other places. However this may be, as it is supposed 

 that a considerable portion of the combustion takes place 

 outside of the muscular substance, it must be expected 

 that, under all the circumstances, far more than J of the 

 whole heat of the combustion of the assimilated nutri- 

 tious matter in animal bodies appears as heat, and only 

 the equivalent of far less than \ is available for mechan- 

 ical labor. For, as we saw, even under the most favora- 

 ble circumstances, about J of the chemical work performed 

 in the muscle itself is inevitably used for the production 

 of heat. But under these most favorable circumstances, 

 however, probably all the muscles do not take part in the 

 labor of the whole body. Therefore, in the acts of living 

 beings we must assume that more than f, probably \ of 

 the result of the work performed in the muscles by chem- 

 ical powers, finally appears as heat. Now, if the material 

 coming into the muscles for combustion should be even 

 a moderate portion, for instance ^of the whole assimilated 

 nutritious matter, while § was consumed elsewhere, then 

 If- of the chemical work performed by the whole combus- 

 tion is used for the mere production of heat, since f of the 

 labor accomplished outside of the muscles can have only 

 the result of producing heat, and of the third coming 

 from the muscle, £ will also produce mere heat. So, un- 

 der this supposition, it must be expected, that at the ut- 

 most the equivalent of ^ of the heat proceeding from 

 the combustion of the nutritious matter would be availa- 

 ble for the mechanical effects of the organism, externally. 



It is already more than twenty years since Hemholtz, 

 by very convincing arguments, proved from facts known 

 at that time, that in seasons of extreme muscular labor, 

 for instance, climbing a mountain, the measureable-me- 

 chanical performances of the whole organism are propor- 

 tionally considerably greater. They are equal to the equiv- 

 alent of about I of the heat of the consumption of the 

 material that burns during the time of these performances, 

 in the v. hole body. Unless the supposition is now made, 

 that the muscles of mammalia can work incomparably 

 more economically than the muscles of the frog — a suppo- 

 sition wholly unjustified by our knowledge of the proper- 

 ties of the muscular substance in the different bodies of 

 animals — we must conclude that, in times of extreme mus- 

 cular activity, the whole process of combustion takes place 

 in the muscles and the chemical processes going on in other 

 parts can only be those in which the chemical powers of at- 

 traction accomplish no considerable labor. In fact, from 

 the results of our experiments concerning the heat of the 

 muscles we have inferred, that by the chemical labor per- 

 formed in the active muscles themselves in the movements 

 of living beings, fully £ is employed in the production of 

 heat ; but if chemical labor was performed in other parts 

 of the body, whose whole result could be only a purely 

 thermal one, more than £ of the chemical labor performed 

 in the whole body must go to the production of heat, and 

 less than i would remain for mechanical external actions. 



If it is once proved, that in times of extreme muscular 

 action the processes, by which the chemical powers of 

 attraction perform labor, take place almost exclusively in 

 the muscles, a similar performance will occur even in 

 times of comparative muscular rest ; for otherwise it must 

 be supposed, that the change of substance during the period 

 of rest takes a totally different direction from that during 

 the time of muscular activity, which is scarcely conceivable. 

 Yet it must be supposed, that in animal bodies a certain 

 kind of combustible material is prepared for the machin- 



ery of the muscles, for which in other portions the condi- 

 tions of combustion do not exist, as coke cannot be burned 

 in a stove arranged for wood. We shall, therefore, be 

 compelled to suppose, that the process of combustion, 

 which renders muscular labor possible, glimmers continu- 

 ally in this texture even in times of rest, only with so little 

 strength, that there is no mechanical action, and only heat 

 is produced. 



There is a very note-worthy harmony between this in- 

 ference and an assertion made by Prliiger and some of 

 his pupils on the basis of very different facts, which is, 

 that in the muscles, even during periods of rest, processes 

 of combustion occur, which are under the influence of the 

 nervous system ; they can be kindled to considerably 

 higher degrees of intensity, before attaining the point 

 requisite for the purpose of a visible mechanical action 

 of the muscle. The .ncrease in the department of these 

 lower degrees of power would, therefore, lead only to an 

 increase of the production of heat, and according to the 

 well-founded hypothesis in question ought to explain the 

 fact, that the development of heat in animal bodies can 

 exist under conditions of the loss of heat externally. 



From all this one would form the following idea of the 

 course of the chemical processes, by which the assimilated 

 nutritious matter is transformed into the rejected matter. 

 The nutritious matter enters into the blood, the liver, and 

 other places only during the chemical processes in which the 

 chemical powers of attiaction either perform no considera- 

 ble work, or in which as many chemical powers of attrac- 

 tion are conquered as come into positive action. These may 

 be partly synthetic performances, partly disunions. Above 

 all, it must be supposed that the greater portion of the 

 nutritious albumen undergoes, directly after its reception 

 into the fluids, a process of this nature, in which a 

 body containing nitrogen is separated, that soon leaves 

 the body under the form of urine. The remnant of the 

 nutritious albumen, free from nitrogen and the other nu- 

 tritious matter r,ch in carbon and hydrogen, is then sup- 

 plied to the muscles as combustible material, perhaps 

 loosely united with the oxygen received by the breath. 

 In action, however, the vast powers of attraciion between 

 the atoms of oxygen on one side and the atoms of car- 

 bon and hydrogen on the other, first enter into the 

 muscular tissue, whereby in the formation of carbonic 

 acid and wa'er, partly heat and partly mechanical effects 

 proceed. 



I should consider the object of these lines attained if I 

 succeeded in showing how a few insignificant thermome- 

 trical experiments in frogs' muscles are capable, from the 

 point of sight of the principle of the preservation of 

 power, of casting a new light on all the particulars of the 

 nourishment of the human body. — 7'ranslated from 

 " Deutsche Rundschau," by M . f. S. 



Dr. T. S. Cobbold exhibited (at the Linnean Society's 

 meeting, November 5) under the microscope about a hun- 

 dred eggs of Bilharzia ha-matobia. They were taken from a 

 gentleman who had just arrived from Egypt, and who was 

 the victim of ha-maturia, supposed to have been contracted 

 during a shooting expedition. By adding water nearly all 

 the eggs were hatched during the meeting of the society, 

 and a rare opportunity was thus afforded of witnessing the 

 behavior of the newly-born ciliated animalcules. 



Donation to Aid Science. Mr. Charles Crocker has 

 made the very handsome donation of $20,000 to the Cali- 

 fornia Academy of Sciences, the income of which is to be 

 devoted to aid worthy and studious investigators in any 

 branch of science, who, by their scientific work, have ex- 

 cluded themselves from acquiring support through the ord- 

 inary avocations of current industrial life. 



M. Paul Bert, the new French Minister for Public In- 

 struction, is said to be a candidate, in the section of Medi- 

 cine, to fill the place vacated in the Academy of Sciences by 

 the recent death ot Dr. Bouillaud. 



