NOTES AND MEMORANDA. 229 



of water in t^'o^ inch cube about 3,700,000,000,000,000. In 

 this and all other cases I give round numbers, since any 

 nearer approximation is impossible. 



Though living organisms contain much water, yet far 

 more complex substances enter into their composition. As 

 an example of one of these, we may take albumen. Accord- 

 ing to Lieberkiihn its composition is expressed by the formula 

 ^r-jH 112^ 18^^22- ^^ therefore contains seventy-one times as 

 many ultimate atoms as water, and its atomic weight is 

 about eighty-two times that of water. In the condition of 

 horn I find that its specific gravity is about 1'31. Calcu- 

 lating from these data, I conclude that when the various con- 

 stituents combine they contract to -,% of the total volume, and 

 not, as water, to f ; and that the volume of a single molecule 

 of albumen is about 55*6 that of a molecule of liquid water. 

 If their form be similar, their diameter must therefore be 

 382 times that of a molecule of water. This would lead us 

 to conclude that in a cube of -pirW of an inch of horn there 

 are about 65,000,000,000,000 molecules of albumen. 



According, then, to these principles there would be in the 

 length of 8-0^^ of an inch of about 2000 molecules of water, 

 or 500 of albumen, and hence, in order to see the ultimate 

 constitution of organic bodies, it would be necessai-y to use a 

 magnifying power of from 500 to 2000 times greater than those 

 we now possess. These, however, for the reasons already 

 given, would be of no use unless the waves of light wer^ 

 some o-oVt P^^'t of the length they are, and our eyes and 

 instruments correspondingly perfect. It will thus be seen 

 that, even with our highest and best powers, we are about as 

 far from seeing the ultimate constitution of organic matter as 

 the naked eye is from seeing the smallest objects which they 

 now reveal to us. Nor does there appear to be much hope that 

 we ever shall see the ultimate constituents, since light itself is 

 manifestly of too coarse a nature, even if it were possible to still 

 further develop our optical resources. As matters now stand 

 we are about as far from a knowledge of the ultimate struc- 

 ture of organic bodies as we should be of the contents of a 

 newspaper seen with the naked eye at a distance of a third 

 of a mile, under which circumstances the letters of various 

 sizes would correspond to the smaller and larger ultimate 

 molecules. This being the case, we may feel persuaded that 

 particles of organic matter, like the spores of many living 

 organisms scarcely visible with the highest magnifying 

 powers, and, if seen, quite undistinguishable from one 

 another, might yet differ in an almost infinite number of 

 structural characters, just as any number of different news- 



