6 THE MICROSCOPE. 



been truly marvellous. There is one point in the 

 history of the microscope which it would be well to 

 bear in mind, because it may show you how much 

 may be done by honest and persevering workers 

 with even inferior instruments. Those who are 

 acquainted with the researches of Leuwenhoek, 

 Grew, and Malpighi, all frequent writers in the early 

 volumes of the Philosophical Transactions, are struck 

 with astonishment at the discoveries they made with 

 instruments so much inferior to those in use at the 

 present day. Truly has an eminent living microscopist 

 and biologist observed with regard to the researches 

 of Leuwenhoek, " That with such imperfect instru- 

 ments at his command, this accurate and painstaking 

 observer should have seen so much and so wetl as to 

 make it dangerous for any one, even now, to an- 

 nounce a discovery without having first consulted his 

 works, in order to see whether some anticipation of it 

 may not be found there, must ever remain a marvel 

 to the microscopist." Of the labours of Grew and 

 Malpighi the same writer remarks "Both were at- 

 tended with great success. The former laid the 

 foundation of our anatomical knowledge of the vege- 

 table tissues, and described their disposition in the 

 roots and stems of a great variety of plants, besides 

 making out many important facts in regard to their 

 physiological action ; the latter did the same for the 

 animal body, and he seems to have been the first to 

 witness the marvellous spectacle of the movement of 

 blood in the capillary vessels of the frog's foot, thus 

 verifying by ocular demonstration that doctrine of 

 the passage of blood from the smallest arteries to the 

 smallest veins, which had been propounded as a ra- 

 tional probability by the sagacious Harvey."* 



A simple microscope is familiar to everybody in the 

 Carpenter on the Microscope, third edition, p. 2, Introduction. 



