An Instance of the Fingerpost by Iain Pears Page A

clear distinction between labour carried out for financial reward, and that done for the improvement of mankind: to put it another way, Lower as a philosopher was fully my equal even if he fell away when he became the practising physician. I think ridiculous the practice of certain professors of anatomy, who find it beneath them to pick up the knife themselves, but merely comment while hired hands do the cutting. Sylvius would never have dreamt of sitting on a dais reading from an authority while others cut – when he taught, the knife was in his hand and the blood spattered his coat. Boyle also did not scruple to perform his own experiments and, on one occasion in my presence, even showed himself willing to anatomise a rat with his very own hands. Nor was he less a gentleman when he had finished. Indeed, in my opinion, his stature was all the greater, for in Boyle wealth, humility and curiosity mingled, and the world is the richer for it.
    ‘Now,’ Boyle said when Lower turned up in mid-afternoon and we took a break from our work, ‘it is time for Cola here to earn the pittance I am paying him.’
    This alarmed me, as I had been labouring hard for at least two hours and I wondered whether perhaps I was doing something wrong, or if Boyle had not noticed my efforts. But rather, he wanted me to sing for my supper, as the phrase goes. I was there not only to learn from him, but also to teach him, such was the marvellous humility of the man.
    ‘Your blood, Cola,’ Lower said to relieve my anxiety. ‘Tell us about your blood. What have you been up to? What experimentations are your conclusions based on? What
are
your conclusions, in fact?’
    ‘I’m very much afraid I am going to disappoint you,’ I began hesitantly when I saw they were not to be diverted. ‘My researches are scarcely advanced. I am mainly interested in the question of what the blood is for. We have known for thirty years that it circulates around the body; your own Harvey showed that. We know that if you drain an animal of its blood, it dies rapidly. The vital spirits in it are the means of communication between the mind and the force of mobility, permitting movement to take place . . .’
    Here Lower wagged his finger. ‘Ah, you have fallen too much under the influence of Mr Helmont, sir. There we will be in dispute.’
    ‘You do not accept this?’
    ‘I do not. Not that it matters, at the moment. Please continue.’
    I regrouped my forces and rethought my approach. ‘We
believe
,’ I started, ‘we
believe
that it moves heat from the ferment of the heart to the brain, thus providing the warmth we need to live, then vents the excess into the lungs. But is that really the case? As far as I know, no experiments have proved this. The other question is simple: why do we breathe? We assume that it is to regulate the body heat, to draw in cool air and thus moderate the blood. Again, is that true? Although the tendency to breathe more often when we exercise indicates this, the converse is not true, for I placed a rat in a bucket of ice and stopped its nose, but it died none the less.’
    Boyle nodded, and Lower looked as though he wanted to put some questions, but as he could see I was concentrating and trying to present my case well, he obligingly refrained from interrupting.
    ‘The other thing that has struck me is the way in which the blood changes consistency. Have you noticed, for example, that it alters colour after passing through the lungs?’
    ‘I confess I have not,’ Lower replied thoughtfully. ‘Although of course I am aware that it changes colour in a jar. But we know why, surely? The heavier melancholic elements in the blood sink, making the top lighter and the bottom darker.’
    ‘Not so,’ I said firmly. ‘Cover the jar, and the colour does not change. And I can find no explanation of how such a separation could occur in the lungs. But when it emerges from the lungs – at least, this is the case in cats – it is very much lighter