SECT. 3] AND EIGHTEENTH CENTURIES 137 



answer to each. But in addition to this, he was also an experimentahst, 

 he had made both anatomical and physical experiments on eggs, 

 and he was prepared to put any disputed point to the test of "ocular 

 aspection", if this could be done. His experimental contributions 

 to embryology come out more clearly in his Commonplace Books which 

 were published by Wilkin in 1836. 



"Runnet beat up with the whites of eggs seems to perform nothing, 

 nor will it well incorporate, without so much heat as will harden 

 the tgg. . . . Eggs seem to contain within themselves their own 

 coagulum, evidenced upon incubation, which makes incrassation of 

 parts before very fluid.. . .Rotten eggs will not be made hard by 

 incubation or decoction, as being destitute of that spirit or having 

 the same vitiated. . . . They will be made hard in oil but not so easily 

 in vinegar which by the attenuating quality keeps them longer from 

 concoction, for infused in vinegar they lose the shell and grow big 

 and much heavier then before. ... In the ovary or second cell of the 

 matrix the white comes upon the yolk, and in the later and lower 

 part, the shell is made or manifested. Try if the same parts will give 

 any coagulation unto milk. Whether will the ovary best?... The 

 whites of eggs drenched in saltpeter will shoot forth a long and hairy 

 saltpeter and the egg become of a hard substance. Even in the whole 

 egg there seems a great nitrosity, for it is very cold and especially 

 that which is without a shell (as some are laid by fat hens) or such 

 as are found in the egg poke or lowest part of the matrix, if an hen 

 be killed a day or two before she layeth. . . . Difference between the 

 sperm of frogs and eggs, spawn though long boiled, would not grow 

 thick and coagulate. In the eggs of skates or thornbacks the yolk 

 coagulates upon long docoction, not the greatest part of the white. . . . 

 In spawn of frogs the little black specks will concrete though not the 

 other. ... In eggs we observe the white will totally freeze, the yolk, with 

 the same degree of cold will grow thick and clammy like the gum of 

 trees, but the sperm or tread hold its former body, the white growing 

 stiff that is nearest to it." 



The only conclusion that can be drawn from these remarkable 

 observations is that it was in the " laboratory " in Sir Thomas' house 

 at Norwich that the first experiments in chemical embryology were 

 undertaken. His significance in this connection has so far been quite 

 overlooked, and it is time to recognise that his originality and genius 

 in this field shows itself to be hardly less remarkable than in so many 



