402 A. B. Hunt — The Crystallisation of Granite. 



The reason I am anxious to press this question of critical 

 temperatures on geologists is, that I feel sure that the majority 

 do not realise the value or perhaps even the existence of the chemical 

 evidence. Professor Hartley has pointed out that the very variation 

 from the true critical temperature of C 2 observed in a microscopic 

 inclusion may suffice to indicate the foreign substance mixed with 

 the C 2, such as nitrogen or hydrochloric acid.^ It is clearly of 

 great importance if the mere magnifying microscope can tell us the 

 gases, fluids, and solids caught up by a crystal, and the temperature 

 of crystallisation. But petrologists obviously either doubt the value 

 of the evidence or are ignorant of it, for students have ere now been 

 rebuked in the most serious and public manner, not for mis- 

 application of the evidence, but for treating it as worthy of credit, 

 while their teachers treat it as though non-existent. I would not 

 ask petrologists to look to this matter if I were able to do so for 

 them. Friends have wished me to make the attempt, but the idea 

 is too ridiculously absurd. The subject involves a profound 

 knowledge of both chemical physics and optical petrology, and 

 I have neither, nor the power to acquire it. When I go into 

 a golf club I have no occasion to ask any individual member how 

 he plays. The club decides that point for him. I look at the list 

 of handicaps, and see at once whether he is an honour man or a poll 

 man. The universities give men their intellectual handicaps, and 

 in the case of diligent workers the university decision is rarely 

 wrong. My own university handicap was one which Huxley would 

 have deemed scarcely fit even for a bishop, as he allowed even 

 bishops first-class polls. But even indifferent golf-players are 

 allowed to enter competitions, which they do with the more than 

 acquiescence of their superiors, who give them points, alias assistance. 

 Since writing this paper I have been impressed with the analogy 

 between the competitions of science and golf. I had to play in a final 

 competition for medallists for a £5 prize, so secured a better player 

 to play me a match and score for me. As a match between ourselves 

 I was successful, with an erratic round including nine fours ; but 

 my whole round, or theory, irretrievably broke down at one hole, 

 which cost me thirteen strokes, instead of the orthodox five. Com- 

 posite science is like medal play at golf. Erratic brilliance is 

 useless ; one fatal flaw in either round or theory is as bad as general 

 incompetence. Now the problem of the plutonic rocks and minerals 

 may be compared to a golf course with many and varied holes. 

 We have physics, optics, chemistry, mineralogy, stratigraphy, and 

 general geology. When our cards are examined at the close of 

 the competition, it will be ascertained whether each difficulty has 

 been individually surmounted. If we pick up our ball at either 

 hole, or are guilty of any breach of the laws of golf, we are fatally 

 disqualified, and notwithstanding phenomenal brilliance at our 

 favourite holes, our medal round, our theory, is of less value than 



' " On Variation in the Critical Point of Carbon Dioxide in Minerals," etc.: 

 Journal Chemical Society, 1876. Keprint, p. 12. 



