77 



SCIENTIFIC SIDE-LIGHTS 



Slackness 

 lood 



what is beheld under the microscope is en- 

 tirely explained when we discover that the 

 red color of blood is due, not to any inherent 

 property of color in blood as a fluid, but to 

 the enormous number of red particles which 

 float in it. What the microscope enables us 

 to see is the clear liquid between the red 

 particles it bears. To the naked eye, which 

 is unable to distinguish minute objects, and 

 which sees things only in the mass, as it 

 were, blood naturally appears red. In any 

 case, it will take its color from its floating 

 particles. 



Some worms have green blood; this is 

 due to the green hue of their blood par- 

 ticles. An oyster or a lobster has colorless 

 blood because it possesses no colored par- 

 ticles at all, but only white or colorless 

 ones. The blood-particles we name " cor- 

 puscles " ; and in addition to the red ones 

 seen in our blood there are also white cor- 

 puscles. The latter are less numerous than 

 the red, and we may calculate that about 

 one white to 400 or 500 red corpuscles is to 

 be taken as a fair or average estimate of 

 their proportion. The red corpuscles of the 

 blood discharge a very important duty in 

 the maintenance of our lives. They are the 

 gas-carriers of the blood. They go forth 

 from the lungs laden with the oxygen we 

 have breathed in; they return to the lungs 

 charged with the carbonic acid gas which 

 we have to breathe out. So far, then, the 

 use and duty of the millions of red particles 

 in our blood are not by any means matters 

 of doubt. ANDREW WILSON Glimpses of Na- 

 ture, ch. 23, p. 74. (Hum., 1892.) 



379. BLOOD-LETTING THE ONCE 



UNIVERSAL CURE Patients Reduced To 

 Keep Down Fever. The doctrine of vital 

 force entered into the pathological system 

 of changes in irritability. The attempt 

 was made to separate the direct actions of 

 the virus which produce disease, in so far 

 as they depended on the play of blind nat- 

 ural forces, the symptomata morbi, from 

 those which brought on the reaction of vital 

 force, the symptomata reactionis. The lat- 

 ter were principally seen in inflammation 

 and in fever. It was the function of the 

 physician to observe the strength of this re- 

 action, and to stimulate or moderate it ac- 

 cording to circumstances. 



The treatment of fever seemed at that 

 time to be the chief point; to be that part 

 of medicine which had a real scientific foun- 

 dation, and in which the local treatment 

 fell comparatively into the background. The 

 therapeutics of febrile diseases had thereby 

 become very monotonous, altho the means 

 indicated by theory were still abundantly 

 used, and especially blood-letting, which 

 since that time has almost been entirely 

 abandoned. HELMHOLTZ Popular Lectures, 

 lect. 5, p. 217. (L. G. & Co., 1898.) 



380. BLOOD POURS TO BRAIN DUR- 

 ING MENTAL ACTIVITY Muscles Drained 



To Supply Higher Life. Mosso . . . dis- 

 covered that the blood-supply to the arms 

 diminished during intellectual activity, and 

 found furthermore that the arterial tension 

 (as shown by the sphygmograph ) was in- 

 creased in these members. . . . The brain 

 itself is an excessively vascular organ, a 

 sponge full of blood, in fact ; and another of 

 Mosso's inventions showed that when less 

 blood went to the arms, more went to the 

 head. The subject to be observed lay on a 

 delicately balanced table which could tip 

 downward either at the head or at the foot 

 if the weight of either end were increased. 

 The moment emotional or intellectual ac- 

 tivity began in the subject, down went the 

 balance at the head-end, in consequence of 

 the redistribution of blood in his system. 

 But the best proof of the immediate afflux 

 of blood to the brain during mental activity 

 is due to Mosso's observations on three per- 

 sons whose brain had been laid bare by 

 lesion of the skull. By means of apparatus 

 described in his book, this physiologist was 

 enabled to let the brain-pulse record itself 

 directly by a tracing. The intracranial 

 blood-pressure rose immediately whenever 

 the subject was spoken to, or when he began 

 to think actively, as in solving a problem in 

 mental arithmetic. JAMES Psychology, vol. 

 i, ch. 3, p. 97. (H. H. & Co., 1899.) 



381. BLOOD, THE AVENGER OF 



Crude Barbaric Justice Hebrew Limita- 

 tion of Ancient Custom. When in barbaric 

 life fierce passion breaks loose and a man is 

 slain, this rule of vengeance comes into ac- 

 tion. How it works as one of the great 

 forces of society may well be seen among 

 the Australians. As Sir George Grey says 

 in his account of it, the holiest duty a na- 

 tive , is called on to perform is to avenge 

 the death of his nearest relation. If he left 

 this duty unfulfilled, the old women would 

 taunt him; if he were unmarried, no girl 

 would speak to him; if he had wives, they 

 would leave him; his mother would cry and 

 lament that she had given birth to so de- 

 generate a son, his father would treat him 

 with contempt, and he would be a mark for 

 public scorn. But what is to be done if the 

 murderer escapes, as must in so wild and 

 thinly peopled a country be easy? Native 

 custom goes on the ancient doctrine that the 

 criminal's whole family are responsible; so 

 that when it is known that a man has been 

 slain, and especially when the actual cul- 

 prit has escaped, his kinsfolk run for their 

 lives; the very children of seven years old 

 know whether they are of kin to the man- 

 slayer, and, if so, they are off at once into 

 hiding. Here, then, we come in view of two 

 principles which every student of law 

 should have clearly in his mind in tracing 

 its history up from its lowest stages. In 

 the primitive law of vengeance of blood, he 

 sees society using for the public benefit the 

 instinct of revenge which man has in com- 

 mon with the lower animals; and by hold- 



